Submission #1179489

#	Time	Username	Problem	Language	Result	Execution time	Memory
1179489		gyg	Catfish Farm (IOI22_fish)	C++20	52 / 100	604 ms	713152 KiB

fish

#include "fish.h"
#include <bits/stdc++.h>
using namespace std;
#define sig signed
#define int long long
#define arr array 
#define vec vector
const int N = 3e3 + 5;

int n;
arr<arr<int, N>, N> a;

arr<arr<int, N>, N> sm;
int rng(int i, int l, int r) {
    if (l > r) return 0;
    return sm[i][r] - sm[i][l - 1];
}
void sm_cmp() {
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n; j++) {
            sm[i][j] = sm[i][j - 1] + a[i][j];
        }
    }
}

arr<arr<arr<arr<int, 2>, N>, N>, 3> mx;
arr<arr<arr<int, 2>, N>, N> dp;
void slv(int i, int x, int b) {
    dp[i][x][b] = rng(i - 1, 1, x);

    if (b == 1) {
        if (i - 1 >= 1) {
            // for (int y = x; y <= n; y++) {
            //     for (int c : {0, 1}) {
            //         dp[i][x][b] = max(dp[i][x][b], dp[i - 1][y][c] + sm[i][y] - sm[i][x]);
            //     }
            // }
            for (int c : {0, 1}) {
                dp[i][x][b] = max(dp[i][x][b], mx[2][i - 1][x][c] - sm[i][x]);
            }
        }
        // cout << i << " " << x << " " << b << ": " << dp[i][x][b] << '\n';
        return;
    }

    if (i - 3 >= 1) {
        // for (int y = 1; y <= n; y++) {
        //     for (int c : {0, 1}) {
        //         dp[i][x][b] = max(dp[i][x][b], dp[i - 3][y][c] + sm[i - 2][y] + sm[i - 1][x]);
        //     }
        // }
        for (int c : {0, 1}) {
            dp[i][x][b] = max(dp[i][x][b], mx[2][i - 3][1][c] + sm[i - 1][x]);
        }
    }
    if (i - 2 >= 1) {
        // for (int y = x; y <= n; y++) {
        //     for (int c : {0, 1}) {
        //         dp[i][x][b] = max(dp[i][x][b], dp[i - 2][y][c] + sm[i - 1][y]);
        //     }
        // }
        for (int c : {0, 1}) {
            dp[i][x][b] = max(dp[i][x][b], mx[2][i - 2][x][c]);
        }
        // for (int y = 1; y <= x - 1; y++) {
        //     for (int c : {0, 1}) {
        //         dp[i][x][b] = max(dp[i][x][b], dp[i - 2][y][c] + sm[i - 1][x]);
        //     }
        // }
        for (int c : {0, 1}) {
            dp[i][x][b] = max(dp[i][x][b], mx[0][i - 2][x - 1][c] + sm[i - 1][x]);
        }
    }
    if (i - 1 >= 1) {
        // for (int y = 1; y <= x - 1; y++) {
        //     dp[i][x][b] = max(dp[i][x][b], dp[i - 1][y][0] - sm[i - 1][y] + sm[i - 1][x]);
        // }
        dp[i][x][b] = max(dp[i][x][b], mx[1][i - 1][x - 1][0] + sm[i - 1][x]);
    }
     
    // cout << i << " " << x << " " << b << ": " << dp[i][x][b] << '\n';
}
void dp_cmp() {
    for (int i = 1; i <= n; i++) {
        for (int x = 1; x <= n; x++) {
            for (int b : {0, 1}) {
                slv(i, x, b);
            }
        }
            
        for (int x = 1; x <= n; x++) {
            for (int b : {0, 1}) {
                mx[0][i][x][b] = max(mx[0][i][x - 1][b], dp[i][x][b]);
                mx[1][i][x][b] = max(mx[1][i][x - 1][b], dp[i][x][b] - sm[i][x]);
            }
        }
        for (int x = n; x >= 1; x--) {
            for (int b : {0, 1}) {
                mx[2][i][x][b] = max(mx[2][i][x + 1][b], dp[i][x][b] + sm[i + 1][x]);
            }
        }
    }
}

int max_weights(sig _n, sig _m, vec<sig> _x, vec<sig> _y, vec<sig> _w) {
    n = _n;
    for (int i = 0; i < _m; i++) a[_x[i] + 1][_y[i] + 1] = _w[i];

    sm_cmp();
    dp_cmp();

    int ans = 0;
    for (int i = 1; i <= n; i++) {
        for (int x = 1; x <= n; x++) {
            for (int b : {0, 1}) {
                ans = max(ans, dp[i][x][b] + rng(i + 1, 1, x));
            }
        }
    }
    return ans;
}

• Subtask 1: 0 / 3
• Subtask 2: 0 / 6
• Subtask 3: 0 / 9
• Subtask 4: 14 / 14
• Subtask 5: 21 / 21
• Subtask 6: 17 / 17
• Subtask 7: 0 / 14
• Subtask 8: 0 / 16