Submission #1141100

#	Time	Username	Problem	Language	Result	Execution time	Memory
1141100		hennessey	Construction Project 2 (JOI24_ho_t2)	C++20	100 / 100	213 ms	22188 KiB

Main

#include <bits/stdc++.h>

using namespace std;

#define int long long

signed main() {
    //your code goes here
    int n, m;
    cin >> n >> m;
    int s, t, l, k;
    cin >> s >> t >> l >> k;
    s--;
    t--;
    vector <vector <pair <int, int>>> adj(n);
    for(int i = 0; i < m; i++) {
        int u, v, w;
        cin >> u >> v >> w;
        u--;
        v--;
        adj[u].push_back({w, v});
        adj[v].push_back({w, u});
    }
    priority_queue <pair <int, int>, vector <pair <int, int>>, greater <pair <int, int>>> pq = {};
    vector <int> dis(n, 1e18);
    dis[s] = 0;
    pq.push({0, s});
    while(!pq.empty()) {
        int v1 = pq.top().first;
        int v2 = pq.top().second;
        pq.pop();
        // cout << v2 << endl;
        if(dis[v2] != v1) {
            continue;
        }
        for(auto i:adj[v2]) {
            int v3 = dis[i.second];
            int v4 = i.first;
            if((v1+v4) < v3) {
                // if(v2 == 0) {
                //     cout << v1 << " " << v4 << " " << dis[i.second] << " " << i.second << endl;
                // }
                dis[i.second] = v1+v4;
                pq.push({v1+v4, i.second});
            }
        }
    }
    vector <int> dis2(n, 1e18);
    dis2[t] = 0;
    pq.push({0, t});
    while(!pq.empty()) {
        int v1 = pq.top().first;
        int v2 = pq.top().second;
        pq.pop();
        // cout << v2 << endl;
        if(dis2[v2] != v1) {
            continue;
        }
        for(auto i:adj[v2]) {
            int v3 = dis2[i.second];
            int v4 = i.first;
            if((v1+v4) < v3) {
                // if(v2 == 0) {
                //     cout << v1 << " " << v4 << " " << dis[i.second] << " " << i.second << endl;
                // }
                dis2[i.second] = v1+v4;
                pq.push({v1+v4, i.second});
            }
        }
    }
    if(dis[t] <= k) {
        cout << n*(n-1)/2 << endl;
    } else {
        int v = k-l;
        int total = 0;
        sort(dis.begin(), dis.end());
        sort(dis2.begin(), dis2.end());
        for(int i = 0; i < n; i++) {
            int v2 = dis[i];
            int v3 = v-v2;
            int v4 = upper_bound(dis2.begin(), dis2.end(), v3)-dis2.begin();
            total += v4;
        }
        cout << total << endl;
    }
    return 0;
}

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