Submission #1164370

#	Time	Username	Problem	Language	Result	Execution time	Memory
1164370		SmuggingSpun	Catfish Farm (IOI22_fish)	C++20	53 / 100	1096 ms	2162688 KiB

fish

#include<bits/stdc++.h>
#include "fish.h"
using namespace std;
typedef long long ll;
const ll INF = 1e18;
template<class T>void maximize(T& a, T b){
    if(a < b){
        a = b;
    }
}
ll max_weights(int n, int m, vector<int>X, vector<int>Y, vector<int>W){
    bool is_sub1 = true;
    for(int& x : X){
        if(x & 1){
            is_sub1 = false;
            break;
        }
    }
    if(is_sub1){
        return accumulate(W.begin(), W.end(), 0LL);
    }
    if(*max_element(X.begin(), X.end()) <= 1){
        if(n > 2){
            ll sum = 0;
            vector<vector<pair<int, int>>>p(2);
            for(int i = 0; i < m; i++){
                if(X[i] == 1){
                    sum += W[i];
                    p[1].emplace_back(Y[i], W[i]);
                }
                else{
                    p[0].emplace_back(Y[i], W[i]);
                }
            }
            p[1].emplace_back(-1, 0);
            sort(p[0].begin(), p[0].end());
            sort(p[1].begin(), p[1].end());
            p[1].emplace_back(n, 0);
            ll ans = sum;
            for(int i = 0, j = 0; j + 1 < p[1].size(); j++){
                sum -= p[1][j].second;
                if(p[1][j].first == p[1][j + 1].first){
                    continue;
                }
                while(i < p[0].size() && p[0][i].first < p[1][j + 1].first){
                    sum += p[0][i].second;
                    i++;
                }
                maximize(ans, sum);
            }
            return ans;
        }
        ll sum_0 = 0, sum_1 = 0;
        for(int i = 0; i < m; i++){
            if(X[i] == 0){
                sum_0 += W[i];
            }
            else{
                sum_1 += W[i];
            }
        }
        return max(sum_0, sum_1);
    }
    if(*max_element(Y.begin(), Y.end()) == 0){
        vector<int>w(n + 1, 0);
        for(int i = 0; i < m; i++){
            w[X[i] + 1] = W[i];
        }
        vector<ll>dp(3, -INF);
        dp[1] = 0;
        for(int i = 1; i <= n; i++){
            vector<ll>ndp(3);
            ndp[0] = max({dp[0], dp[1] + w[i - 1], dp[2]});
            ndp[1] = max(dp[1], dp[2]);
            ndp[2] = dp[0] + w[i];
            swap(dp, ndp);
        }      
        return max({dp[0], dp[1], dp[2]});
    }
    if(n <= 300){
        vector<vector<ll>>w(n + 2, vector<ll>(n + 2, 0));
        for(int i = 0; i < m; i++){
            w[X[i] + 1][Y[i] + 1] = W[i];
        }
        for(int i = 1; i <= n; i++){
            for(int j = 1; j <= n; j++){
                w[i][j] += w[i][j - 1];
            }
        }
        vector<vector<ll>>dp(n + 2, vector<ll>(3, -INF));
        for(int i = 0; i <= n; i++){
            dp[i][0] = 0;
        }
        for(int i = 1; i <= n; i++){
            vector<vector<ll>>ndp(n + 2, vector<ll>(3, -INF));
            ndp[0][0] = dp[0][0];
            ll init_12 = 0, init_sub_12 = -INF;
            for(int j = 0; j <= n; j++){
                maximize(init_12, dp[j][0]);
                maximize(init_sub_12, dp[j][0] - w[i - 1][j]);
            }
            ll temp = 0;
            for(int j = 1; j <= n; j++){
                maximize(temp, dp[j][1] - w[i - 1][j]);
                ndp[j][1] = max(ndp[j][2] = max(init_12, init_sub_12 + w[i - 1][j]), temp + w[i - 1][j]);
                for(int k = 1; k <= j; k++){
                    maximize(ndp[j][1], dp[k][1] + w[i - 1][j] - w[i - 1][k]);
                }
                for(int k = j; k <= n; k++){
                    maximize(ndp[j][2], dp[k][2] + w[i][k] - w[i][j]);
                }
                maximize(ndp[j][0], max(dp[j][1], dp[j][2]) + w[i][j]);
                maximize(ndp[0][0], dp[j][0]);
            }
            temp = 0;
            for(int j = n; j > 0; j--){
                maximize(temp, dp[j][2] + w[i][j]);
                maximize(ndp[j][2], temp - w[i][j]);
            }
            swap(dp, ndp);
        }
        ll ans = 0;
        for(int i = 0; i <= n; i++){
            maximize(ans, max({dp[i][0], dp[i][1], dp[i][2]}));
        }
        return ans;
    }
}

Compilation message (stderr)

fish.cpp: In function 'll max_weights(int, int, std::vector<int>, std::vector<int>, std::vector<int>)':
fish.cpp:128:1: warning: control reaches end of non-void function [-Wreturn-type]
  128 | }
      | ^

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