Submission #490566

#TimeUsernameProblemLanguageResultExecution timeMemory
490566vijayMecho (IOI09_mecho)Java
24 / 100
781 ms65540 KiB
import java.io.*;
import java.util.*;

public class mecho {
    static int N, S;
    static int[][] distFromHive;
    static int startX, startY, endX, endY;
    static int[] dX, dY;
    static boolean[][] forest;
    public static void main(String[] args) throws IOException, FileNotFoundException {
        InputReader in = new InputReader();
        // Scanner in = new Scanner(new File("test.in"));

        N = in.nextInt();
        S = in.nextInt();

        forest = new boolean[N][N];

        PriorityQueue<State> pq = new PriorityQueue<>();

        for(int i = 0; i < N; i++){
            String line = in.nextString();
            for(int j = 0; j < N; j++){
                int cchar = line.charAt(j);
                if(cchar == 'T'){
                    forest[i][j] = true;
                } else if (cchar == 'M'){
                    startX = i;
                    startY = j;
                } else if (cchar == 'D'){
                    endX = i;
                    endY = j;
                } else if (cchar == 'H'){
                    pq.add(new State(i, j, 0));
                }
            } 
        }

        distFromHive = new int[N][N];
        for(int i = 0; i < N; i++){
            Arrays.fill(distFromHive[i], -1);
        }

        dX = new int[] {-1, 1, 0, 0};
        dY = new int[] {0, 0, -1, 1};

        while(!pq.isEmpty()){
            State curr = pq.poll();
            if(distFromHive[curr.x][curr.y] != -1){
                continue;
            }
            distFromHive[curr.x][curr.y] = curr.dist;
            for(int i = 0; i < 4; i++){
                int nX = curr.x + dX[i];
                int nY = curr.y + dY[i];
                if(nX < 0 || nX >= N || nY < 0 || nY >= N || forest[nX][nY]){
                    continue;
                }
                pq.add(new State(nX, nY, curr.dist + 1));
            }
        }

        // for(int i = 0; i < N; i++){
        //     System.out.println(Arrays.toString(distFromHive[i]));
        // }

        int a = 0;
        int b = 640000000;
        while(a != b){
            int mid = (a + b + 1)/2;
            if(works(mid)){
                a = mid;
            } else {
                b = mid - 1;
            }
        }

        System.out.println(a);
    }

    public static boolean works(int wait){
        PriorityQueue<State> pq = new PriorityQueue<>();
        pq.add(new State(startX, startY, wait * S));
        boolean[][] visited = new boolean[N][N];
        while(!pq.isEmpty()){
            State curr = pq.poll();
            if(visited[curr.x][curr.y]){
                continue;
            }

            if(curr.x == endX && curr.y == endY){
                // System.out.println("get to " + curr.x + " " + curr.y + " in " + curr.dist + " vs. " + distFromHive[curr.x][curr.y]);
                return true;
            }

            if(distFromHive[curr.x][curr.y] * S <= curr.dist){
                continue;
            }

            for(int i = 0; i < 4; i++){
                int nX = curr.x + dX[i];
                int nY = curr.y + dY[i];
                if(nX < 0 || nX >= N || nY < 0 || nY >= N || forest[nX][nY]){
                    continue;
                }
                pq.add(new State(nX, nY, curr.dist + 1));
            }
        }
        return false;
    }

    public static class State implements Comparable<State>{
        int x, y, dist;
        public State(int x, int y, int dist){
            this.x = x;
            this.y = y;
            this.dist = dist;
        }
        public int compareTo(State s){
            return dist - s.dist;
        }
    }

    public static class InputReader {

        /**
         * The default size of the InputReader's buffer is 2<sup>16</sup>.
         */
        private static final int DEFAULT_BUFFER_SIZE = 1 << 16;

        /**
         * The default stream for the InputReader is standard input.
         */
        private static final InputStream DEFAULT_STREAM = System.in;

        /**
         * The maximum number of accurate decimal digits the method {@link #nextDoubleFast() nextDoubleFast()} can read.
         * Currently this value is set to 21 because it is the maximum number of digits a double precision float can have at the moment.
         */
        private static final int MAX_DECIMAL_PRECISION = 21;

        // 'c' is used to refer to the current character in the stream
        private int c;

        // Variables associated with the byte buffer.
        private byte[] buf;
        private int bufferSize, bufIndex, numBytesRead;

        private InputStream stream;

        // End Of File (EOF) character
        private static final byte EOF   = -1;

        // New line character: '\n'
        private static final byte NEW_LINE = 10;

        // Space character: ' '
        private static final byte SPACE = 32;

        // Dash character: '-'
        private static final byte DASH  = 45;

        // Dot character: '.'
        private static final byte DOT   = 46;

        // A reusable character buffer when reading string data.
        private char[] charBuffer;

        // Primitive data type lookup tables used for optimizations
        private static byte[] bytes = new byte[58];
        private static  int[] ints  = new int[58];
        private static char[] chars = new char[128];

        static {
            char ch = ' '; int value = 0; byte _byte = 0;
            for (int i = 48; i <  58; i++ ) bytes[i] = _byte++;
            for (int i = 48; i <  58; i++ )  ints[i] = value++;
            for (int i = 32; i < 128; i++ ) chars[i] = ch++;
        }

        // Primitive double lookup table used for optimizations.
        private static final double[][] doubles = {
                { 0.0d,0.00d,0.000d,0.0000d,0.00000d,0.000000d,0.0000000d,0.00000000d,0.000000000d,0.0000000000d,0.00000000000d,0.000000000000d,0.0000000000000d,0.00000000000000d,0.000000000000000d,0.0000000000000000d,0.00000000000000000d,0.000000000000000000d,0.0000000000000000000d,0.00000000000000000000d,0.000000000000000000000d },
                { 0.1d,0.01d,0.001d,0.0001d,0.00001d,0.000001d,0.0000001d,0.00000001d,0.000000001d,0.0000000001d,0.00000000001d,0.000000000001d,0.0000000000001d,0.00000000000001d,0.000000000000001d,0.0000000000000001d,0.00000000000000001d,0.000000000000000001d,0.0000000000000000001d,0.00000000000000000001d,0.000000000000000000001d },
                { 0.2d,0.02d,0.002d,0.0002d,0.00002d,0.000002d,0.0000002d,0.00000002d,0.000000002d,0.0000000002d,0.00000000002d,0.000000000002d,0.0000000000002d,0.00000000000002d,0.000000000000002d,0.0000000000000002d,0.00000000000000002d,0.000000000000000002d,0.0000000000000000002d,0.00000000000000000002d,0.000000000000000000002d },
                { 0.3d,0.03d,0.003d,0.0003d,0.00003d,0.000003d,0.0000003d,0.00000003d,0.000000003d,0.0000000003d,0.00000000003d,0.000000000003d,0.0000000000003d,0.00000000000003d,0.000000000000003d,0.0000000000000003d,0.00000000000000003d,0.000000000000000003d,0.0000000000000000003d,0.00000000000000000003d,0.000000000000000000003d },
                { 0.4d,0.04d,0.004d,0.0004d,0.00004d,0.000004d,0.0000004d,0.00000004d,0.000000004d,0.0000000004d,0.00000000004d,0.000000000004d,0.0000000000004d,0.00000000000004d,0.000000000000004d,0.0000000000000004d,0.00000000000000004d,0.000000000000000004d,0.0000000000000000004d,0.00000000000000000004d,0.000000000000000000004d },
                { 0.5d,0.05d,0.005d,0.0005d,0.00005d,0.000005d,0.0000005d,0.00000005d,0.000000005d,0.0000000005d,0.00000000005d,0.000000000005d,0.0000000000005d,0.00000000000005d,0.000000000000005d,0.0000000000000005d,0.00000000000000005d,0.000000000000000005d,0.0000000000000000005d,0.00000000000000000005d,0.000000000000000000005d },
                { 0.6d,0.06d,0.006d,0.0006d,0.00006d,0.000006d,0.0000006d,0.00000006d,0.000000006d,0.0000000006d,0.00000000006d,0.000000000006d,0.0000000000006d,0.00000000000006d,0.000000000000006d,0.0000000000000006d,0.00000000000000006d,0.000000000000000006d,0.0000000000000000006d,0.00000000000000000006d,0.000000000000000000006d },
                { 0.7d,0.07d,0.007d,0.0007d,0.00007d,0.000007d,0.0000007d,0.00000007d,0.000000007d,0.0000000007d,0.00000000007d,0.000000000007d,0.0000000000007d,0.00000000000007d,0.000000000000007d,0.0000000000000007d,0.00000000000000007d,0.000000000000000007d,0.0000000000000000007d,0.00000000000000000007d,0.000000000000000000007d },
                { 0.8d,0.08d,0.008d,0.0008d,0.00008d,0.000008d,0.0000008d,0.00000008d,0.000000008d,0.0000000008d,0.00000000008d,0.000000000008d,0.0000000000008d,0.00000000000008d,0.000000000000008d,0.0000000000000008d,0.00000000000000008d,0.000000000000000008d,0.0000000000000000008d,0.00000000000000000008d,0.000000000000000000008d },
                { 0.9d,0.09d,0.009d,0.0009d,0.00009d,0.000009d,0.0000009d,0.00000009d,0.000000009d,0.0000000009d,0.00000000009d,0.000000000009d,0.0000000000009d,0.00000000000009d,0.000000000000009d,0.0000000000000009d,0.00000000000000009d,0.000000000000000009d,0.0000000000000000009d,0.00000000000000000009d,0.000000000000000000009d }
        };

        /**
         * Create an InputReader that reads from standard input.
         */
        public InputReader () {
            this(DEFAULT_STREAM, DEFAULT_BUFFER_SIZE);
        }

        /**
         * Create an InputReader that reads from standard input.
         * @param bufferSize    The buffer size for this input reader.
         */
        public InputReader(int bufferSize) {
            this(DEFAULT_STREAM, bufferSize);
        }

        /**
         * Create an InputReader that reads from standard input.
         * @param stream  Takes an InputStream as a parameter to read from.
         */
        public InputReader(InputStream stream) {
            this(stream, DEFAULT_BUFFER_SIZE);
        }

        /**
         * Create an InputReader that reads from standard input.
         * @param  stream        Takes an {@link java.io.InputStream#InputStream() InputStream} as a parameter to read from.
         * @param  bufferSize    The size of the buffer to use.
         */
        public InputReader (InputStream stream, int bufferSize) {
            if (stream == null || bufferSize <= 0)
                throw new IllegalArgumentException();
            buf = new byte[bufferSize];
            charBuffer = new char[128];
            this.bufferSize = bufferSize;
            this.stream = stream;
        }

        /**
         * Reads a single character from the input stream.
         * @return Returns the byte value of the next character in the buffer and EOF
         * at the end of the stream.
         * @throws IOException throws exception if there is no more data to read
         */
        private byte read() throws IOException {

            if (numBytesRead == EOF) throw new IOException();

            if (bufIndex >= numBytesRead) {
                bufIndex = 0;
                numBytesRead = stream.read(buf);
                if (numBytesRead == EOF)
                    return EOF;
            }

            return buf[bufIndex++];
        }

        /**
         *  Read values from the input stream until you reach a character with a
         *  higher ASCII value than 'token'.
         * @param token The token is a value which we use to stop reading junk out of
         * the stream.
         * @return Returns 0 if a value greater than the token was reached or -1 if
         * the end of the stream was reached.
         * @throws IOException Throws exception at end of stream.
         */
        private int readJunk(int token) throws IOException {

            if (numBytesRead == EOF) return EOF;

            // Seek to the first valid position index
            do {

                while(bufIndex < numBytesRead) {
                    if (buf[bufIndex] > token) return 0;
                    bufIndex++;
                }

                // reload buffer
                numBytesRead = stream.read(buf);
                if (numBytesRead == EOF) return EOF;
                bufIndex = 0;

            } while(true);

        }

        /**
         * Reads a single byte from the input stream.
         * @return The next byte in the input stream
         * @throws IOException Throws exception at end of stream.
         */
        public byte nextByte() throws IOException {
            return (byte) nextInt();
        }

        /**
         * Reads a 32 bit signed integer from input stream.
         * @return The next integer value in the stream.
         * @throws IOException Throws exception at end of stream.
         */
        public int nextInt() throws IOException {

            if (readJunk(DASH-1) == EOF) throw new IOException();
            int sgn = 1, res = 0;

            c = buf[bufIndex];
            if (c == DASH) { sgn = -1; bufIndex++; }

            do {

                while(bufIndex < numBytesRead) {
                    if (buf[bufIndex] > SPACE) {
                        res = (res<<3)+(res<<1);
                        res += ints[buf[bufIndex++]];
                    } else {
                        bufIndex++;
                        return res*sgn;
                    }
                }

                // Reload buffer
                numBytesRead = stream.read(buf);
                if (numBytesRead == EOF) return res*sgn;
                bufIndex = 0;

            } while(true);

        }

        /**
         * Reads a 64 bit signed long from input stream.
         * @return The next long value in the stream.
         * @throws IOException Throws exception at end of stream.
         */
        public long nextLong() throws IOException {

            if (readJunk(DASH-1) == EOF) throw new IOException();
            int sgn = 1;
            long res = 0L;
            c = buf[bufIndex];
            if (c == DASH) { sgn = -1; bufIndex++; }

            do {

                while(bufIndex < numBytesRead) {
                    if (buf[bufIndex] > SPACE) {
                        res = (res<<3)+(res<<1);
                        res += ints[buf[bufIndex++]];
                    } else {
                        bufIndex++;
                        return res*sgn;
                    }
                }

                // Reload buffer
                numBytesRead = stream.read(buf);
                if (numBytesRead == EOF) return res*sgn;
                bufIndex = 0;

            } while(true);

        }

        /**
         * Doubles the size of the internal char buffer for strings
         */
        private void doubleCharBufferSize() {
            char[] newBuffer = new char[charBuffer.length << 1];
            for(int i = 0; i < charBuffer.length; i++) newBuffer[i] = charBuffer[i];
            charBuffer = newBuffer;
        }

        /**
         * Reads a line from the input stream.
         * @return Returns a line from the input stream in the form a String not
         * including the new line character. Returns <code>null</code> when there are
         * no more lines.
         * @throws IOException Throws IOException when something terrible happens.
         */
        public String nextLine() throws IOException {

            try { c=read(); } catch (IOException e) { return null; }
            if (c == NEW_LINE) return ""; // Empty line
            if (c == EOF) return null; // EOF

            int i = 0;
            charBuffer[i++] = (char)c;

            do {

                while(bufIndex < numBytesRead) {
                    if (buf[bufIndex] != NEW_LINE) {
                        if (i == charBuffer.length) doubleCharBufferSize();
                        charBuffer[i++] = (char) buf[bufIndex++];
                    } else {
                        bufIndex++;
                        return new String(charBuffer, 0, i);
                    }
                }

                // Reload buffer
                numBytesRead = stream.read(buf);
                if (numBytesRead == EOF)
                    return new String(charBuffer, 0, i);
                bufIndex = 0;

            } while(true);

        }

        // Reads a string of characters from the input stream.
        // The delimiter separating a string of characters is set to be:
        // any ASCII value <= 32 meaning any spaces, new lines, EOF, tabs...
        public String nextString() throws IOException {
            if (numBytesRead == EOF) return null;
            if (readJunk(SPACE) == EOF) return null;

            for(int i = 0;;) {
                while(bufIndex < numBytesRead) {
                    if (buf[bufIndex] > SPACE) {
                        if (i == charBuffer.length) doubleCharBufferSize();
                        charBuffer[i++] = (char) buf[bufIndex++];
                    } else {
                        bufIndex++;
                        return new String(charBuffer, 0, i);
                    }
                }

                // Reload buffer
                numBytesRead = stream.read(buf);
                if (numBytesRead == EOF) return new String(charBuffer, 0, i);
                bufIndex = 0;
            }
        }

        // Returns an exact value a double value from the input stream.
        public double nextDouble() throws IOException {
            String doubleVal = nextString();
            if (doubleVal == null) throw new IOException();
            return Double.valueOf(doubleVal);
        }

        // Very quickly reads a double value from the input stream (~3x faster than nextDouble()). However,
        // this method may provide a slightly less accurate reading than .nextDouble() if there are a lot
        // of digits (~16+). In particular, it will only read double values with at most 21 digits after
        // the decimal point and the reading my be as inaccurate as ~5*10^-16 from the true value.
        public double nextDoubleFast() throws IOException {
            c = read(); int sgn = 1;
            while (c <= SPACE) c = read(); // while c is either: ' ', '\n', EOF
            if (c == DASH) { sgn = -1; c = read(); }
            double res = 0.0;
            // while c is not: ' ', '\n', '.' or -1
            while (c > DOT) {res *= 10.0; res += ints[c]; c = read(); }
            if (c == DOT) {
                int i = 0; c = read();
                // while c is digit and we are less than the maximum decimal precision
                while (c > SPACE && i < MAX_DECIMAL_PRECISION) {
                    res += doubles[ints[c]][i++]; c = read();
                }
            }
            return res * sgn;
        }

        // Read an array of n byte values
        public byte[] nextByteArray(int n) throws IOException {
            byte[] ar = new byte[n];
            for (int i = 0; i < n; i++) ar[i] = nextByte();
            return ar;
        }

        // Read an integer array of size n
        public int[] nextIntArray(int n) throws IOException {
            int[] ar = new int[n];
            for (int i = 0; i < n; i++) ar[i] = nextInt();
            return ar;
        }

        // Read a long array of size n
        public long[] nextLongArray(int n) throws IOException {
            long[] ar = new long[n];
            for (int i = 0; i < n; i++) ar[i] = nextLong();
            return ar;
        }

        // read an of doubles of size n
        public double[] nextDoubleArray(int n) throws IOException {
            double[] ar = new double[n];
            for (int i = 0; i < n; i++) ar[i] = nextDouble();
            return ar;
        }

        // Quickly read an array of doubles
        public double[] nextDoubleArrayFast(int n) throws IOException {
            double[] ar = new double[n];
            for (int i = 0; i < n; i++) ar[i] = nextDoubleFast();
            return ar;
        }

        // Read a string array of size n
        public String[] nextStringArray(int n) throws IOException {
            String[] ar = new String[n];
            for (int i = 0; i < n; i++) {
                String str = nextString();
                if (str == null) throw new IOException();
                ar[i] = str;
            }
            return ar;
        }

        // Read a 1-based byte array of size n+1
        public byte[] nextByteArray1(int n) throws IOException {
            byte[] ar = new byte[n+1];
            for (int i = 1; i <= n; i++) ar[i] = nextByte();
            return ar;
        }

        // Read a 1-based integer array of size n+1
        public int[] nextIntArray1(int n) throws IOException {
            int[] ar = new int[n+1];
            for (int i = 1; i <= n; i++) ar[i] = nextInt();
            return ar;
        }

        // Read a 1-based long array of size n+1
        public long[] nextLongArray1(int n) throws IOException {
            long[] ar = new long[n+1];
            for (int i = 1; i <= n; i++) ar[i] = nextLong();
            return ar;
        }

        // Read a 1-based double array of size n+1
        public double[] nextDoubleArray1(int n) throws IOException {
            double[] ar = new double[n+1];
            for (int i = 1; i <= n; i++) ar[i] = nextDouble();
            return ar;
        }

        // Quickly read a 1-based double array of size n+1
        public double[] nextDoubleArrayFast1(int n) throws IOException {
            double[] ar = new double[n+1];
            for (int i = 1; i <= n; i++) ar[i] = nextDoubleFast();
            return ar;
        }

        // Read a 1-based string array of size n+1
        public String[] nextStringArray1(int n) throws IOException {
            String[] ar = new String[n+1];
            for (int i = 1; i <= n; i++) ar[i] = nextString();
            return ar;
        }

        // Read a two dimensional matrix of bytes of size rows x cols
        public byte[][] nextByteMatrix(int rows, int cols) throws IOException {
            byte[][] matrix = new byte[rows][cols];
            for(int i = 0; i < rows; i++)
                for (int j = 0; j < cols; j++)
                    matrix[i][j] = nextByte();
            return matrix;
        }

        // Read a two dimensional matrix of ints of size rows x cols
        public int[][] nextIntMatrix(int rows, int cols) throws IOException {
            int[][] matrix = new int[rows][cols];
            for(int i = 0; i < rows; i++)
                for (int j = 0; j < cols; j++)
                    matrix[i][j] = nextInt();
            return matrix;
        }

        // Read a two dimensional matrix of longs of size rows x cols
        public long[][] nextLongMatrix(int rows, int cols) throws IOException {
            long[][] matrix = new long[rows][cols];
            for(int i = 0; i < rows; i++)
                for (int j = 0; j < cols; j++)
                    matrix[i][j] = nextLong();
            return matrix;
        }

        // Read a two dimensional matrix of doubles of size rows x cols
        public double[][] nextDoubleMatrix(int rows, int cols) throws IOException {
            double[][] matrix = new double[rows][cols];
            for(int i = 0; i < rows; i++)
                for (int j = 0; j < cols; j++)
                    matrix[i][j] = nextDouble();
            return matrix;
        }

        // Quickly read a two dimensional matrix of doubles of size rows x cols
        public double[][] nextDoubleMatrixFast(int rows, int cols) throws IOException {
            double[][] matrix = new double[rows][cols];
            for(int i = 0; i < rows; i++)
                for (int j = 0; j < cols; j++)
                    matrix[i][j] = nextDoubleFast();
            return matrix;
        }

        // Read a two dimensional matrix of Strings of size rows x cols
        public String[][] nextStringMatrix(int rows, int cols) throws IOException {
            String[][] matrix = new String[rows][cols];
            for(int i = 0; i < rows; i++)
                for (int j = 0; j < cols; j++)
                    matrix[i][j] = nextString();
            return matrix;
        }

        // Read a 1-based two dimensional matrix of bytes of size rows x cols
        public byte[][] nextByteMatrix1(int rows, int cols) throws IOException {
            byte[][] matrix = new byte[rows+1][cols+1];
            for(int i = 1; i <= rows; i++)
                for (int j = 1; j <= cols; j++)
                    matrix[i][j] = nextByte();
            return matrix;
        }

        // Read a 1-based two dimensional matrix of ints of size rows x cols
        public int[][] nextIntMatrix1(int rows, int cols) throws IOException {
            int[][] matrix = new int[rows+1][cols+1];
            for(int i = 1; i <= rows; i++)
                for (int j = 1; j <= cols; j++)
                    matrix[i][j] = nextInt();
            return matrix;
        }

        // Read a 1-based two dimensional matrix of longs of size rows x cols
        public long[][] nextLongMatrix1(int rows, int cols) throws IOException {
            long[][] matrix = new long[rows+1][cols+1];
            for(int i = 1; i <= rows; i++)
                for (int j = 1; j <= cols; j++)
                    matrix[i][j] = nextLong();
            return matrix;
        }

        // Read a 1-based two dimensional matrix of doubles of size rows x cols
        public double[][] nextDoubleMatrix1(int rows, int cols) throws IOException {
            double[][] matrix = new double[rows+1][cols+1];
            for(int i = 1; i <= rows; i++)
                for (int j = 1; j <= cols; j++)
                    matrix[i][j] = nextDouble();
            return matrix;
        }

        // Quickly read a 1-based two dimensional matrix of doubles of size rows x cols
        public double[][] nextDoubleMatrixFast1(int rows, int cols) throws IOException {
            double[][] matrix = new double[rows+1][cols+1];
            for(int i = 1; i <= rows; i++)
                for (int j = 1; j <= cols; j++)
                    matrix[i][j] = nextDoubleFast();
            return matrix;
        }

        // Read a 1-based two dimensional matrix of Strings of size rows x cols
        public String[][] nextStringMatrix1(int rows, int cols) throws IOException {
            String[][] matrix = new String[rows+1][cols+1];
            for(int i = 1; i <= rows; i++)
                for (int j = 1; j <= cols; j++)
                    matrix[i][j] = nextString();
            return matrix;
        }

        // Closes the input stream
        public void close() throws IOException {
            stream.close();
        }

    }
}
#Verdict Execution timeMemoryGrader output
Fetching results...