Submission #1158317

#	Time	Username	Problem	Language	Result	Execution time	Memory
1158317		InvMOD	Catfish Farm (IOI22_fish)	C++20	61 / 100	378 ms	536984 KiB

fish

#include<bits/stdc++.h>

//#define name "InvMOD"
#ifndef name
    #include "fish.h"
#endif // name

using namespace std;

#define fi first
#define se second

//#define int long long
#define sz(v) (int)(v).size()
#define all(v) (v).begin(), (v).end()
#define dbg(x) "[" << #x " = " << (x) << "]"

using ll = long long;

namespace Subtask1{
    bool ckSub(vector<int>& X){
        for(int i = 0; i < sz(X); i++){
            if(X[i] & 1) return false;
        }
        return true;
    }

    ll process(vector<int>& W){
        ll answer = 0;
        for(int i = 0; i < sz(W); i++){
            answer += W[i];
        }
        return answer;
    }
}

namespace Subtask2{
    bool ckSub(vector<int>& X){
        for(int i = 0; i < sz(X); i++){
            if(X[i] > 1) return false;
        }
        return true;
    }

    ll process(int n, vector<int>& X, vector<int>& Y, vector<int>& W){
        vector<vector<int>> row(2, vector<int>(n + 1));

        vector<ll> sum(2, 0);
        for(int i = 0; i < sz(X); i++){
            row[X[i]][Y[i] + 1] = W[i];
            sum[X[i]] += 1ll * W[i];
        }

        ll answer = max(sum[0], sum[1]), pref = 0;
        if(n > 2){
            for(int i = 1; i <= n; i++){
                pref += row[0][i];
                sum[1] -= row[1][i];

                answer = max(answer, pref + sum[1]);
            }
        }
        return answer;
    }
}

namespace Subtask45{
    bool ckSub(int n){
        return n <= 300;
    }

    ll process(int n, vector<int>& X, vector<int>& Y, vector<int>& W){
        vector<vector<int>> row(n + 1, vector<int>(n + 1));

        for(int i = 0; i < sz(X); i++){
            row[X[i] + 1][Y[i] + 1] = W[i];
        }

        vector<vector<ll>> pref(n + 1, vector<ll>(n + 1));

        for(int i = 1; i <= n; i++){
            for(int j = 1; j <= n; j++){
                pref[i][j] = pref[i][j - 1] + row[i][j];
            }
        }

        vector<vector<ll>> f(n + 1, vector<ll>(n + 1));
        vector<vector<ll>> g(n + 1, vector<ll>(n + 1));

        // f[i][j]: did not take from j + 1 -> n
        // g[i][j]: take from j + 1 -> n

        for(int i = 1; i <= n; i++){
            for(int r = 0; r <= n; r++){
                for(int l = 0; l <= n; l++){
                    f[i][r] = max(f[i][r], f[i - 1][l] + max(0ll, pref[i - 1][r] - pref[i - 1][l]));
                    f[i][r] = max(f[i][r], g[i - 1][l]);
                }
                //cout << i <<" " << r <<" " << dbg(f[i][r]) << "\n";
            }

            if(i > 1){
                for(int r = 0; r <= n; r++){
                    for(int l = 0; l <= n; l++){
                        g[i][r] = max(g[i][r], f[i - 1][l] +
                                      max(0ll, pref[i - 1][r] - pref[i - 1][l]) +
                                      max(0ll, pref[i][l] - pref[i][r]));
                        g[i][r] = max(g[i][r], g[i - 1][l] + max(0ll, pref[i][l] - pref[i][r]));
                    }
                    //cout << i <<" " << r <<" " << dbg(g[i][r]) << "\n";
                }
            }
        }

        ll answer = 0;
        for(int i = 1; i <= n; i++){
            for(int j = 0; j <= n; j++){
                answer = max(answer, f[i][j]);
                answer = max(answer, g[i][j]);
            }
        }

        return answer;
    }
}

namespace Subtask6{
    bool ckSub(int n){
        return n <= 3000;
    }

    ll process(int n, vector<int>& X, vector<int>& Y, vector<int>& W){
        vector<vector<int>> row(n + 1, vector<int>(n + 1));

        for(int i = 0; i < sz(X); i++){
            row[X[i] + 1][Y[i] + 1] = W[i];
        }

        vector<vector<ll>> pref(n + 1, vector<ll>(n + 1));

        for(int i = 1; i <= n; i++){
            for(int j = 1; j <= n; j++){
                pref[i][j] = pref[i][j - 1] + row[i][j];
            }
        }

        vector<vector<ll>> f(n + 1, vector<ll>(n + 1));
        vector<vector<ll>> g(n + 1, vector<ll>(n + 1));

        // f[i][j]: did not take from j + 1 -> n
        // g[i][j]: take from j + 1 -> n

        vector<vector<ll>> pMx(n + 1, vector<ll>(n + 1));
        vector<vector<ll>> sMx(n + 1, vector<ll>(n + 1));

        vector<vector<ll>> sgMx(n + 1, vector<ll>(n + 1));
        vector<vector<ll>> pgMx(n + 1, vector<ll>(n + 1));

        for(int i = 1; i <= n; i++){
            for(int l = 0; l <= n; l++){
                pMx[i - 1][l] = f[i - 1][l] - pref[i - 1][l];
                pgMx[i - 1][l] = g[i - 1][l];
                if(l > 0){
                    pMx[i - 1][l] = max(pMx[i - 1][l], pMx[i - 1][l - 1]);
                    pgMx[i - 1][l] = max(pgMx[i - 1][l], pgMx[i - 1][l - 1]);
                }
            }

            for(int r = 0; r <= n; r++){
                /*
                for(int l = 0; l <= n; l++){
                    f[i][r] = max(f[i][r], f[i - 1][l] + max(0ll, pref[i - 1][r] - pref[i - 1][l]));
                    f[i][r] = max(f[i][r], g[i - 1][l]);
                }
                */
                f[i][r] = max(f[i][r], pMx[i - 1][r] + pref[i - 1][r]);
                f[i][r] = max(f[i][r], pgMx[i - 1][n]);

                //cout << i <<" " << r <<" " << dbg(f[i][r]) << "\n";
            }

            if(i > 1){
                for(int l = n; l >= 0; l--){
                    sMx[i - 1][l] = f[i - 1][l] + pref[i][l];
                    sgMx[i - 1][l] = g[i - 1][l] + pref[i][l];

                    if(l < n){
                        sMx[i - 1][l] = max(sMx[i - 1][l], sMx[i - 1][l + 1]);
                        sgMx[i - 1][l] = max(sgMx[i - 1][l], sgMx[i - 1][l + 1]);
                    }
                }
                for(int r = 0; r <= n; r++){
                    /*
                    for(int l = 0; l <= n; l++){
                        g[i][r] = max(g[i][r], f[i - 1][l] +
                                      max(0ll, pref[i - 1][r] - pref[i - 1][l]) +
                                      max(0ll, pref[i][l] - pref[i][r]));
                        g[i][r] = max(g[i][r], g[i - 1][l] + max(0ll, pref[i][l] - pref[i][r]));
                    }
                    */
//                    g[i][r] = max(g[i][r], pMx[i - 1][r] + pref[i - 1][r]);
                    g[i][r] = max(g[i][r], sMx[i - 1][r] - pref[i][r]);
//                    g[i][r] = max(g[i][r], pgMx[i - 1][r]);
                    g[i][r] = max(g[i][r], sgMx[i - 1][r] - pref[i][r]);
                    //cout << i <<" " << r <<" " << dbg(g[i][r]) << "\n";
                }
            }
        }

        ll answer = 0;
        for(int i = 1; i <= n; i++){
            for(int j = 0; j <= n; j++){
                answer = max(answer, f[i][j]);
                answer = max(answer, g[i][j]);
            }
        }

        return answer;
    }
}

ll max_weights(int n, int m, vector<int> X, vector<int> Y, vector<int> W){

    if(Subtask1::ckSub(X)){
        return Subtask1::process(W);
    }

    if(Subtask2::ckSub(X)){
        return Subtask2::process(n, X, Y, W);
    }

    if(Subtask6::ckSub(n)){
        return Subtask6::process(n, X, Y, W);
    }

    if(Subtask45::ckSub(n)){
        return Subtask45::process(n, X, Y, W);
    }

    return 0;
}

#ifdef name
    int32_t main(){
        freopen(name".INP", "r", stdin);
        freopen(name".OUT", "w", stdout);

        int n,m; cin >> n >> m;

        vector<int> X(m), Y(m), W(m);

        for(int i = 0; i < m; i++){
            cin >> X[i];
        }
        for(int i = 0; i < m; i++){
            cin >> Y[i];
        }
        for(int i = 0; i < m; i++){
            cin >> W[i];
        }

        cout << max_weights(n, m, X, Y, W) << "\n";

        return 0;
    }
#endif // name

• Subtask 1: 3 / 3
• Subtask 2: 6 / 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