Submission #834735

#	Time	Username	Problem	Language	Result	Execution time	Memory
834735		tengiz05	Catfish Farm (IOI22_fish)	C++17	52 / 100	737 ms	436988 KiB

fish

#include "fish.h"

#include <bits/stdc++.h>
using namespace std;
using i64 = long long;

constexpr int N = 3000;
constexpr i64 inf = 1E18;

i64 dp[N + 1][N + 1][2];
i64 pre[N + 1][N + 1];

void chmax(i64 &a, i64 b) {
    if (a < b) {
        a = b;
    }
}

long long max_weights(int n, int m, std::vector<int> X, std::vector<int> Y,
                      std::vector<int> W) {
    for (int i = 0; i < m; i++) {
        pre[X[i]][Y[i] + 1] += W[i];
    }
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            pre[i][j + 1] += pre[i][j];
        }
    }
    
    memset(dp, 190, sizeof dp);
    
    for (int i = 0; i <= n; i++) {
        dp[0][i][0] = dp[0][i][1] = 0;
    }
    for (int i = 1; i < n; i++) {
        i64 best = -inf;
        for (int k = 0; k <= n; k++) {
            chmax(best, dp[i - 1][k][0] - pre[i - 1][k]);
            chmax(dp[i][k][0], best + pre[i - 1][k]);
        }
        best = -inf;
        for (int k = n; k >= 0; k--) {
            chmax(best, dp[i - 1][k][1] + pre[i][k]);
            chmax(dp[i][k][1], best - pre[i][k]);
        }
        if (i >= 2) {
            best = -inf;
            for (int j = n; j >= 0; j--) {
                chmax(best, dp[i - 2][j][1] + pre[i - 1][j]);
                chmax(dp[i][j][0], best);
            }
            best = -inf;
            for (int j = 0; j <= n; j++) {
                chmax(best, dp[i - 2][j][1]);
                chmax(dp[i][j][0], best + pre[i - 1][j]);
            }
        }
        for (int j = 0; j <= n; j++) {
            chmax(dp[i][j][1], dp[i][j][0]);
        }
        if (i + 1 < n)
            chmax(dp[i + 1][0][0], dp[i][0][1]);
    }
    
    i64 ans = 0;
    for (int i = 0; i <= n; i++) {
        ans = max(ans, dp[n - 1][i][1]);
    }
    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