Submission #47011

#	Time	Username	Problem	Language	Result	Execution time	Memory
47011		SpaimaCarpatilor	Abduction 2 (JOI17_abduction2)	C++17	100 / 100	2244 ms	109272 KiB

abduction2

#include<bits/stdc++.h>

using namespace std;

int H, W, Q, L[50009], C[50009], lg[50009], rmqL[16][50009], rmqC[16][50009];
unordered_map < long long, long long > mp;

void getJ1J2 (int j, int &j1, int &j2, int minVal)
{
    j1 = j, j2 = j;
    for (int k=lg[j]; k>=0; k--)
        if (j1 - (1 << k) + 1 >= 1 && rmqC[k][j1 - (1 << k) + 1] <= minVal)
            j1 -= (1 << k);
    for (int k=lg[W - j + 1]; k>=0; k--)
        if (j2 + (1 << k) - 1 <= W && rmqC[k][j2] <= minVal)
            j2 += (1 << k);
}

void getI1I2 (int i, int &i1, int &i2, int minVal)
{
    i1 = i, i2 = i;
    for (int k=lg[i]; k>=0; k--)
        if (i1 - (1 << k) + 1 >= 1 && rmqL[k][i1 - (1 << k) + 1] <= minVal)
            i1 -= (1 << k);
    for (int k=lg[H - i + 1]; k>=0; k--)
        if (i2 + (1 << k) - 1 <= H && rmqL[k][i2] <= minVal)
            i2 += (1 << k);
}

long long solve (int i, int j)
{
    long long currPos = 1LL * i * W + j;
    if (mp.count (currPos))
        return mp[currPos];
    long long ans = 0;
    if (L[i] > C[j])
    {
        int j1, j2;
        getJ1J2 (j, j1, j2, L[i]);

        if (j1 == 0) ans = max (ans, (long long) j - 1);
        else
        {
            long long curr = solve (i, j1) + j - j1;
            ans = max (ans, curr);
        }

        if (j2 == W + 1) ans = max (ans, (long long) W - j);
        else
        {
            long long curr = solve (i, j2) + j2 - j;
            ans = max (ans, curr);
        }
    }
    else
    {
        int i1, i2;
        getI1I2 (i, i1, i2, C[j]);

        if (i1 == 0) ans = max (ans, (long long) i - 1);
        else
        {
            long long curr = solve (i1, j) + i - i1;
            ans = max (ans, curr);
        }

        if (i2 == H + 1) ans = max (ans, (long long) H - i);
        else
        {
            long long curr = solve (i2, j) + i2 - i;
            ans = max (ans, curr);
        }
    }
    mp[currPos] = ans;
    return ans;
}

void read ()
{
    scanf ("%d %d %d", &H, &W, &Q);
    for (int i=1; i<=H; i++)
        scanf ("%d", &L[i]), rmqL[0][i] = L[i];
    for (int j=1; j<=W; j++)
        scanf ("%d", &C[j]), rmqC[0][j] = C[j];
    for (int i=1; i<=max (H, W); i++)
    {
        lg[i] = lg[i - 1];
        if ((2 << lg[i]) <= i) lg[i] ++;
    }
    for (int i=1; i<=lg[H]; i++)
        for (int j=1; j + (1 << i) - 1 <= H; j++)
            rmqL[i][j] = max (rmqL[i - 1][j], rmqL[i - 1][j + (1 << (i - 1))]);
    for (int i=1; i<=lg[W]; i++)
        for (int j=1; j + (1 << i) - 1 <= W; j++)
            rmqC[i][j] = max (rmqC[i - 1][j], rmqC[i - 1][j + (1 << (i - 1))]);
}

int dx[] = {-1, 1, 0, 0};
int dy[] = {0, 0, -1, 1};
int oh[] = {0, 0, 1, 1};

bool valid (int i, int j)
{
    return (1 <= i && i <= H && 1 <= j && j <= W);
}

int main ()
{
//freopen ("input", "r", stdin);
//freopen ("output", "w", stdout);

read ();
while (Q --)
{
    int x, y;
    long long ans = 0;
    scanf ("%d %d", &x, &y);
    for (int k=0; k<4; k++)
    {
        int i = x + dx[k], j = y + dy[k], steps = 1;
        while (1)
        {
            if (!valid (i, j)) break;
            if ((L[i] > C[j]) != oh[k])
            {
                long long curr = solve (i, j) + steps;
                if (curr > ans)
                    ans = curr;
                break;
            }
            if (steps > ans)
                ans = steps;
            steps ++, i += dx[k], j += dy[k];
        }
    }
    printf ("%lld\n", ans);
}

return 0;
}

Compilation message (stderr)

abduction2.cpp: In function 'void read()':
abduction2.cpp:80:11: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf ("%d %d %d", &H, &W, &Q);
     ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
abduction2.cpp:82:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf ("%d", &L[i]), rmqL[0][i] = L[i];
         ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~
abduction2.cpp:84:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf ("%d", &C[j]), rmqC[0][j] = C[j];
         ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~
abduction2.cpp: In function 'int main()':
abduction2.cpp:117:11: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf ("%d %d", &x, &y);
     ~~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 10 / 10
• Subtask 3: 17 / 17
• Subtask 4: 4 / 4
• Subtask 5: 56 / 56