제출 #1172721

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1172721		SmuggingSpun	Construction Project 2 (JOI24_ho_t2)	C++20	100 / 100	505 ms	76016 KiB

Main

#include<bits/stdc++.h>
#define taskname "B"
using namespace std;
typedef long long ll;
const int lim = 2e5 + 5;
const ll INF = 1e18;
template<class T>bool minimize(T& a, T b){
    if(a > b){
        a = b;
        return true;
    }
    return false;
}
int n, m, s, t, L;
ll K;
namespace sub2{
    void solve(){
        vector<vector<ll>>d(n + 1, vector<ll>(n + 1, INF));
        for(int i = 0; i < m; i++){
            int u, v, w;
            cin >> u >> v >> w;
            d[u][v] = d[v][u] = w;            
        }
        int ans = 0;
        for(int i = 1; i < n; i++){
            for(int j = n; j > i; j--){
                vector<vector<ll>>_d = d;
                minimize(_d[i][j], ll(L));
                minimize(_d[j][i], ll(L));
                for(int k = 1; k <= n; k++){
                    for(int u = 1; u <= n; u++){
                        for(int v = 1; v <= n; v++){
                            minimize(_d[u][v], _d[u][k] + _d[k][v]);
                        }
                    }
                }
                if(_d[s][t] <= K){
                    ans++;
                }
            }
        }
        cout << ans;
    }
}
vector<pair<int, int>>g[lim];
vector<ll>dijkstra(int start){
    vector<ll>d(n + 1, INF);
    priority_queue<pair<ll, int>, vector<pair<ll, int>>, greater<pair<ll, int>>>pq;
    pq.emplace(d[start] = 0, start);
    while(!pq.empty()){
        auto [ud, u] = pq.top();
        pq.pop();
        if(ud == d[u]){
            for(auto& [v, w] : g[u]){
                if(minimize(d[v], ud + w)){
                    pq.emplace(d[v], v);
                }
            }
        }
    }
    return d;
}
namespace sub3{
    void solve(){
        vector<vector<ll>>d(n + 1);
        for(int i = 1; i <= n; i++){
            d[i] = dijkstra(i);
        }
        if(d[s][t] <= K){
            return void(cout << ((n * (n - 1)) >> 1));
        }
        int ans = 0;
        for(int i = 1; i < n; i++){
            for(int j = n; j > i; j--){
                if(min(d[s][i] + d[j][t], d[s][j] + d[i][t]) + L <= K){
                    ans++;
                }
            }
        }
        cout << ans;
    }
}
namespace sub14{
    void solve(){
        vector<ll>ds = dijkstra(s), dt = dijkstra(t);
        if(ds[t] <= K){
            return void(cout << ((1LL * n * (n - 1)) >> 1LL));
        }
        sort(ds.begin(), ds.end());
        sort(dt.begin(), dt.end());
        ll ans = 0;
        for(int i = 0, j = n - 1; i < n; i++){
            while(j > -1 && ds[i] + dt[j] + L > K){
                j--;
            }
            ans += j + 1;
        }
        cout << ans;
    }
}
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	if(fopen(taskname".inp", "r")){
		freopen(taskname".inp", "r", stdin);
	}
    cin >> n >> m >> s >> t >> L >> K;
    if(n <= 50 && m <= 50){
        sub2::solve();
    }
    else{
        for(int i = 0; i < m; i++){
            int u, v, w;
            cin >> u >> v >> w;
            g[u].emplace_back(v, w);
            g[v].emplace_back(u, w);
        }
        if(n <= 3000){
            sub3::solve();
        }
        else{
            sub14::solve();
        }
    }
}

컴파일 시 표준 에러 (stderr) 메시지

Main.cpp: In function 'int main()':
Main.cpp:104:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  104 |                 freopen(taskname".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 16 / 16
• Subtask 3: 29 / 29
• Subtask 4: 47 / 47