Submission #1212255

#	Time	Username	Problem	Language	Result	Execution time	Memory
1212255		stefanneagu	Construction Project 2 (JOI24_ho_t2)	C++20	0 / 100	2 ms	5136 KiB

Main

#include <bits/stdc++.h>
#define int long long

using namespace std;

const int nmax = 2e5 + 1, inf = 1e18;

vector<pair<int, int>> adj[nmax];
int d1[nmax];
int d2[nmax];
int n;

void dij1(int root) {
    for (int i = 1; i <= n; i++) {
        d1[i] = inf;
    }
    priority_queue<pair<int, int>> pq;
    pq.push({0, root});
    d1[root] = 0;
    while (!pq.empty()) {
        auto [sum, i] = pq.top();
        pq.pop();
        if (sum > d1[i]) {
            continue;
        }
        for (auto [it, c] : adj[i]) {
            if (d1[it] > sum + c) {
                d1[it] = sum + c;
                pq.push({d1[it], it});
            }
        }
    }
}

void dij2(int root) {
    for (int i = 1; i <= n; i++) {
        d2[i] = inf;
    }
    priority_queue<pair<int, int>> pq;
    pq.push({0, root});
    d2[root] = 0;
    while (!pq.empty()) {
        auto [sum, i] = pq.top();
        pq.pop();
        if (sum > d2[i]) {
            continue;
        }
        for (auto [it, c] : adj[i]) {
            if (d2[it] > sum + c) {
                d2[it] = sum + c;
                pq.push({d2[it], it});
            }
        }
    }
}

int32_t main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int m, s, t, c, k;
    cin >> n >> m >> s >> t >> c >> k;
    for (int i = 1; i <= m; i++) {
        int a, b, c;
        cin >> a >> b >> c;
        adj[a].push_back({b, c});
        adj[b].push_back({a, c});
    }
    dij1(s);
    dij2(t);
    vector<int> v;
    v.push_back(-inf);
    for (int i = 1; i <= n; i++) {
        v.push_back(d2[i]);
    }
    cout << '\n';
    sort(v.begin(), v.end());
    int ans = 0;
    for (int i = 1; i <= n; i++) {
        int ind = lower_bound(v.begin(), v.end(), k - d1[i] - c) - v.begin();
        if (v[ind] + d1[i] + c > k) {
            ind--;
        }
        ans += ind;
        if (d1[i] + c + d2[i] == k) {
            ans--;
        }
    }
    cout << ans;
    return 0;
}

• Subtask 1: 0 / 8
• Subtask 2: 0 / 16
• Subtask 3: 0 / 29
• Subtask 4: 0 / 47