Submission #1212246

#	Time	Username	Problem	Language	Result	Execution time	Memory
1212246		trinm01	Construction Project 2 (JOI24_ho_t2)	C++20	45 / 100	2092 ms	18876 KiB

Main

#include <bits/stdc++.h>
using namespace std;

#define int long long
#define ll long long
#define FOR(i, l, r) for (int i = (l); i <= (r); i++)
#define FOD(i, r, l) for (int i = (r); i >= (l); i--)
#define fi first
#define se second
#define pii pair<int, int>

const ll mod = 1e9 + 7;
const ll MAXN = 2e5 + 5;
const int oo = 1e18;
const int base = 320;

int n, m, s, t, l, k, f[2][MAXN];
vector<pii> adj[MAXN];

void dijsktra(int ty, int a){
    priority_queue<pii, vector<pii>, greater<pii>> q;
    FOR(i, 1, n){
        f[ty][i]=oo;
    }
    f[ty][a]=0;
    q.push({0, a});
    while(q.size()){
        auto [c, u]=q.top();
        q.pop();
        if(c>f[ty][u]) continue;
        for(auto [v, w]:adj[u]){
            if(f[ty][v]>f[ty][u]+w){
                f[ty][v]=f[ty][u]+w;
                q.push({f[ty][v], v});
            }
        }
    }
}

signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    if (fopen(".INP", "r"))
    {
        freopen(".INP", "r", stdin);
        freopen(".OUT", "w", stdout);
    }       

    cin >> n >> m >> s >> t >> l >> k;
    FOR(i, 1, m){
        int u, v, c;
        cin >> u >> v >> c;
        adj[u].push_back({v, c});
        adj[v].push_back({u, c});
    }

    dijsktra(0, s);
    dijsktra(1, t);

    int dem=0;
    FOR(i, 1, n){
        FOR(j, i+1, n){
            if(f[0][i]+f[1][j]+l<=k || f[0][j]+f[1][i]+l<=k){
                // cout << i << ' ' << j << '\n';
                dem++;
            }
            else if(f[0][t]<=k){
                dem++;
            }
        }
    }
    // cout << f[1][3] << ' ';
    cout << dem;


    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:47:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   47 |         freopen(".INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~
Main.cpp:48:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |         freopen(".OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~

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