Submission #1083838

#	Time	Username	Problem	Language	Result	Execution time	Memory
1083838		SamueleVid	Catfish Farm (IOI22_fish)	C++17	9 / 100	64 ms	10856 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; 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 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) minore_di_due = 0;
    return res_y_zero(N, M, X, Y, W);
}

Compilation message (stderr)

fish.cpp: In function 'long long int max_weights(int, int, std::vector<int>, std::vector<int>, std::vector<int>)':
fish.cpp:92:10: warning: unused variable 'y_zero' [-Wunused-variable]
   92 |     bool y_zero = 1;
      |          ^~~~~~

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