Submission #1083851

#	Time	Username	Problem	Language	Result	Execution time	Memory
1083851		SamueleVid	Catfish Farm (IOI22_fish)	C++17	18 / 100	284 ms	180560 KiB

fish

#include <bits/stdc++.h>
using namespace std;
#define ll long long

constexpr int MAXN = 1e5 + 5;

ll sum_tutto(int N, int M, vector<int> X, vector<int> Y, vector<int> W) {
    ll sum = 0;
    for (auto x : W) sum += x;
    return sum;
}

ll res_minore_di_due(int N, int M, vector<int> X, vector<int> Y, vector<int> W) {
    if (N == 2) {
        // massimo tra 0 e 1    
        ll one = 0;
        ll zero = 0;
        for (int i = 0; i < M; i ++) {
            if (X[i] == 0) zero += W[i];
            else one += W[i];
        }

        return max(one, zero);
    }

    // altrimenti piazza una riga in 2 e poi prendi prefisso maggiore piazzando in 1
    
    ll sum = 0;
    for (int i = 0; i < M; i ++) {
        if (X[i] == 1) sum += W[i];
    }

    vector<vector<ll>> pos(2, vector<ll>(N + 5, 0));

    for (int i = 0; i < M; i ++) {
        pos[X[i]][Y[i]] += W[i];
    }

    ll best_res = sum;

    ll sum_zero = 0;
    ll sum_uno = 0;
    for (int i = 0; i < N + 5; i ++) {
        sum_zero += pos[0][i];
        sum_uno += pos[1][i];
        best_res = max(best_res, sum - sum_uno + sum_zero);
    }

    return best_res;
}

ll res_y_zero(int N, int M, vector<int> X, vector<int> Y, vector<int> W) {
    vector<vector<ll>> dp(2, vector<ll>(N + 5)); // posso prendere a sx o no, posizione

    vector<ll> grid(N + 5);
    for (int i = 0; i < M; i ++) grid[X[i]] = W[i];

    for (int i = N - 1; i >= 0; i --) {
        dp[0][i] = dp[1][i + 1];
        dp[0][i] = max(dp[0][i], dp[0][i + 1]);
        dp[0][i] = max(dp[0][i], dp[0][i + 2] + grid[i + 1]);
        dp[0][i] = max(dp[0][i], dp[1][i + 3] + grid[i + 1]);
        dp[0][i] = max(dp[0][i], dp[0][i + 3] + grid[i + 1]);

        if (i != 0) {
            dp[1][i] = dp[1][i + 1];
            dp[1][i] = max(dp[1][i], dp[0][i + 1] + grid[i - 1]);
            dp[1][i] = max(dp[1][i], dp[0][i + 2] + grid[i - 1] + grid[i + 1]); 
            dp[1][i] = max(dp[1][i], dp[1][i + 3] + grid[i - 1] + grid[i + 1]); 
            dp[1][i] = max(dp[1][i], dp[0][i + 3] + grid[i - 1] + grid[i + 1]); 
        }
    }

    ll best_res = 0;
    for (int i = 0; i <= N; i ++) {
        best_res = max(best_res, dp[0][i]);
        best_res = max(best_res, dp[1][i]);
    }
    return best_res;
}

ll cubic(int N, int M, vector<int> X, vector<int> Y, vector<int> W) {
    // i, quanto lo alzo, quanto era alzato a destra
    int MAXY = min(N, 9);
    ll dp[N + 5][MAXY + 5][MAXY + 5]; 

    for (int i = 0; i < N + 5; i ++) {
        for (int j = 0; j < MAXY + 5; j ++) {
            for (int k = 0; k < MAXY + 5; k ++) {
                dp[i][j][k] = 0;
            }
        }
    }

    ll grid[N + 5][MAXY + 5];
    for (int i = 0; i < N + 5; i ++) {
        for (int j = 0; j < MAXY + 5; j ++) {
                grid[i][j] = 0;
        }
    }

    for (int i = 0; i < M; i ++) grid[X[i]][Y[i]] = W[i];

    ll ps_grid[N + 5][MAXY + 5]; // 1 based per le Y

    for (int i = 0; i < N + 5; i ++) {
        ps_grid[i][0] = 0;
        for (int j = 0; j < MAXY + 4; j ++) {
            ps_grid[i][j + 1] = ps_grid[i][j] + grid[i][j];
        }
    }

    // cout << "N, MAXY : " << N << " " << MAXY << '\n';

    // cout << "grid : " << '\n';
    // for (int i = 0; i < N + 5; i ++) {
    //     for (int j = 0; j < MAXY + 5; j ++) {
    //         cout << grid[i][j] << " ";
    //     }
    //     cout << '\n';
    // }
    // cout << "ps_grid " << '\n';
    // for (int i = 0; i < N + 5; i ++) {
    //     for (int j = 0; j < MAXY + 5; j ++) {
    //         cout << ps_grid[i][j] << " ";
    //     }
    //     cout << '\n';
    // }

    for (int i = N - 1; i >= 0; i --) {
        for (int y = 0; y <= MAXY; y ++) {
            for (int dx = 0; dx <= MAXY; dx ++) {
                // quanto mi alzo
                for (int dxdx = 0; dxdx <= MAXY; dxdx ++) {
                    // cout << "-- i, y, dx, dxdx : " << i << " " << y << " " << dx << " " << dxdx << '\n';
                    // cout << "dp dopo : " << dp[i + 1][dx][dxdx] << '\n';
                    // cout << "a dx preso top : " << ps_grid[i + 1][y] << " e si sottrae " << ps_grid[i + 1][max(dx, dxdx)] << '\n';
                    int preso = -ps_grid[i][min(dx, y)];
                    if (y > max(dx, dxdx)) {
                        preso += ps_grid[i + 1][y] - ps_grid[i + 1][max(dx, dxdx)];
                    }
                    if (i > 0) {
                        preso += ps_grid[i - 1][y];
                        // cout << " e poi si aggiunge a sx " << ps_grid[i - 1][y] << '\n';
                    }

                    // cout << "preso : " << preso << '\n';
                    // cout << "new value : " << dp[i + 1][dx][dxdx] + preso << '\n';

                    dp[i][y][dx] = max(dp[i][y][dx], dp[i + 1][dx][dxdx] + preso);
                }
            }
        }
    }

    ll res = 0;
    for (int i = 0; i < N; i ++) {
        for (int y = 0; y < MAXY; y ++) {
            for (int dx = 0; dx < MAXY; dx ++) {
                res = max(res, dp[i][y][dx]);
            }
        }
    }

    return res;
}


ll max_weights(int N, int M, vector<int> X, vector<int> Y, vector<int> W) {
    bool all_even = 1;
    for (auto x : X) if (x % 2) all_even = 0;
    if (all_even) return sum_tutto(N, M, X, Y, W);

    bool minore_di_due = 1;
    for (auto x : X) if (x >= 2) minore_di_due = 0;
    if (minore_di_due) return res_minore_di_due(N, M, X, Y, W);

    bool y_zero = 1;
    for (auto y : Y) if (y > 0) y_zero = 0;
    if (y_zero) return res_y_zero(N, M, X, Y, W);

    return cubic(N, M, X, Y, W);
}

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