# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
333135 | KWang31 | Split the sequence (APIO14_sequence) | Java | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
//By Spontaneous Combustion, just used for test
import java.io.*;
import java.util.*;
public class Main {
public static void main(final String[] args) throws IOException {
final int N = readInt();
final int K = readInt();
final long[] sum = new long[N + 1];
for (int i = 1; i <= N; i++) {
sum[i] = sum[i - 1] + readInt();
}
final LineContainer lines = new LineContainer(N);
final long[][] dp = new long[2][N];
for (int i = 1; i < N; i++) {
dp[1][i] = sum[i] * (sum[N] - sum[i]);
}
final int[][] prevSplit = new int[K][N];
for (int i = 1, curr = 0, prev = 1; i < K; i++, curr ^= 1, prev ^= 1) {
lines.clear();
for (int j = i + 1; j < N; j++) {
lines.addLine(j - 1, sum[j - 1], -sum[j - 1] * sum[N] + dp[prev][j - 1]);
dp[curr][j] = sum[j] * sum[N] - sum[j] * sum[j] + lines.maxValue(sum[j]);
prevSplit[i][j] = lines.getCurrentIndex();
}
}
long maxPoints = Long.MIN_VALUE;
int idx = -1;
int curr = K & 1;
for (int i = K; i < N; i++) {
if (dp[curr][i] > maxPoints) {
maxPoints = dp[curr][i];
idx = i;
}
}
System.out.println(maxPoints);
for (int i = idx, splitsLeft = K; splitsLeft > 0; splitsLeft--, i = prevSplit[splitsLeft][i]) {
System.out.print(i + " ");
}
System.out.println();
}
private static final class LineContainer {
private final long[] slopes;
private final long[] yInts;
private final int[] indexes;
private int lines = 0;
private int idx = 0;
public LineContainer(final int capacity) {
this.slopes = new long[capacity];
this.yInts = new long[capacity];
this.indexes = new int[capacity];
}
public void addLine(final int index, final long slope, final long yInt) {
if (lines > 0 && slopes[lines - 1] == slope && yInts[lines - 1] == yInt) {
return;
}
while (lines >= 2 && intersectionX(slopes[lines - 2], yInts[lines - 2], slope,
yInt) < intersectionX(slopes[lines - 2], yInts[lines - 2], slopes[lines - 1], yInts[lines - 1])) {
--lines;
}
indexes[lines] = index;
slopes[lines] = slope;
yInts[lines++] = yInt;
}
public long maxValue(final long x) {
while (idx + 1 < lines && slopes[idx + 1] * x + yInts[idx + 1] >= slopes[idx] * x + yInts[idx]) {
++idx;
}
return slopes[idx] * x + yInts[idx];
}
public int getCurrentIndex() {
return indexes[idx];
}
public void clear() {
idx = lines = 0;
}
private static long intersectionX(final long slope1, final long yInt1, final long slope2, final long yInt2) {
return (yInt2 - yInt1) / (slope1 - slope2);
}
}
private static final int BUFFER_SIZE = 1 << 16;
private static final InputStream in = System.in;
private static final byte[] buffer = new byte[BUFFER_SIZE];
private static int bufferPointer = 0, bytesRead = 0;
public static String read() throws IOException {
final StringBuilder sb = new StringBuilder();
byte c = Read();
while (c <= ' ') {
c = Read();
}
do {
sb.append((char) c);
c = Read();
} while (c != -1 && c != ' ' && c != '\n' && c != '\r');
return sb.toString();
}
public static String read(final int length) throws IOException {
final byte[] ret = new byte[length];
int idx = 0;
byte c = Read();
while (c <= ' ') {
c = Read();
}
do {
ret[idx++] = c;
c = Read();
} while (c != -1 && c != ' ' && c != '\n' && c != '\r');
return new String(ret, 0, idx);
}
public static String[] readStringArray(final int strings) throws IOException {
final String[] arr = new String[strings];
for (int i = 0; i < strings; i++) {
arr[i] = read();
}
return arr;
}
public static String readLine() throws IOException {
final StringBuilder sb = new StringBuilder();
byte c = Read();
while (c == '\n' || c == '\r') {
c = Read();
}
do {
sb.append((char) c);
c = Read();
} while (c != -1 && c != '\n' && c != '\r');
return sb.toString();
}
public static char readChar() throws IOException {
byte c = Read();
while (Character.isWhitespace(c)) {
c = Read();
}
return (char) c;
}
private static char[] readCharArray(final int chars) throws IOException {
final char[] arr = new char[chars];
for (int i = 0; i < chars; i++) {
arr[i] = readChar();
}
return arr;
}
public static java.math.BigInteger readBigInteger() throws IOException {
return new java.math.BigInteger(read());
}
public static java.math.BigDecimal readBigDecimal() throws IOException {
return new java.math.BigDecimal(read());
}
public static byte readByte() throws IOException {
byte ret = 0;
byte c = Read();
while (c <= ' ')
c = Read();
boolean neg = (c == '-');
if (neg)
c = Read();
do {
ret = (byte) (ret * 10 + c - '0');
} while ((c = Read()) >= '0' && c <= '9');
if (neg)
return (byte) -ret;
return ret;
}
public static byte[] readByteArray(final int numbers) throws IOException {
final byte[] arr = new byte[numbers];
for (int i = 0; i < numbers; i++) {
arr[i] = readByte();
}
return arr;
}
public static short readShort() throws IOException {
short ret = 0;
byte c = Read();
while (c <= ' ')
c = Read();
boolean neg = (c == '-');
if (neg)
c = Read();
do {
ret = (short) (ret * 10 + c - '0');
} while ((c = Read()) >= '0' && c <= '9');
if (neg)
return (short) -ret;
return ret;
}
public static short[] readShortArray(final int numbers) throws IOException {
final short[] arr = new short[numbers];
for (int i = 0; i < numbers; i++) {
arr[i] = readShort();
}
return arr;
}
public static int readInt() throws IOException {
int ret = 0;
byte c = Read();
while (c <= ' ')
c = Read();
boolean neg = (c == '-');
if (neg)
c = Read();
do {
ret = ret * 10 + c - '0';
} while ((c = Read()) >= '0' && c <= '9');
if (neg)
return -ret;
return ret;
}
public static int[] readIntArray(final int numbers) throws IOException {
final int[] arr = new int[numbers];
for (int i = 0; i < numbers; i++) {
arr[i] = readInt();
}
return arr;
}
public static long readLong() throws IOException {
long ret = 0;
byte c = Read();
while (c <= ' ')
c = Read();
boolean neg = (c == '-');
if (neg)
c = Read();
do {
ret = ret * 10 + c - '0';
} while ((c = Read()) >= '0' && c <= '9');
if (neg)
return -ret;
return ret;
}
public static long[] readLongArray(final int numbers) throws IOException {
final long[] arr = new long[numbers];
for (int i = 0; i < numbers; i++) {
arr[i] = readLong();
}
return arr;
}
public static double readDouble() throws IOException {
double ret = 0, div = 1;
byte c = Read();
while (c <= ' ')
c = Read();
boolean neg = (c == '-');
if (neg)
c = Read();
do {
ret = ret * 10 + c - '0';
} while ((c = Read()) >= '0' && c <= '9');
if (c == '.') {
while ((c = Read()) >= '0' && c <= '9') {
ret += (c - '0') / (div *= 10);
}
}
if (neg)
return -ret;
return ret;
}
public static double[] readDoubleArray(final int numbers) throws IOException {
final double[] arr = new double[numbers];
for (int i = 0; i < numbers; i++) {
arr[i] = readDouble();
}
return arr;
}
private static void fillBuffer() throws IOException {
bytesRead = in.read(buffer, bufferPointer = 0, BUFFER_SIZE);
if (bytesRead == -1)
buffer[0] = -1;
}
private static byte Read() throws IOException {
if (bufferPointer == bytesRead)
fillBuffer();
return buffer[bufferPointer++];
}
}