Submission #1242054

#	Time	Username	Problem	Language	Result	Execution time	Memory
1242054		Geforgs	Construction Project 2 (JOI24_ho_t2)	C++20	100 / 100	217 ms	30196 KiB

Main

#include <iostream>
#include <iomanip>
#include <vector>
#include <cmath>
#include <algorithm>
#include <set>
#include <queue>
#include <map>
#include <unordered_map>
#include <stack>
#include <bitset>
#include <string>
#include <cstring>
#include <iterator>
#include <random>
#define ll long long
#define ld long double
#define inf (ll)(2*1e18)
#define sort(a) sort(a.begin(), a.end())
#define reverse(a) reverse(a.begin(), a.end())
#define pb push_back
#define endl "\n"
using namespace std;

void Dijkstra(ll start, vector<vector<pair<ll, ll>>>& a, vector<ll>& dis){
    set<pair<ll, ll>> s;
    s.insert({0, start});
    dis[start] = 0;
    while(!s.empty()){
        auto [val, x] = *s.begin();
        s.erase(s.begin());
        for(auto [y, w]: a[x]){
            if(dis[y] > val + w){
                s.erase({dis[y], y});
                dis[y] = val + w;
                s.insert({dis[y], y});
            }
        }
    }
}

void solve(){
    ll n, m, k, l, i, start, finish, x, y, w, res=0;
    cin>>n>>m>>start>>finish>>l>>k;
    --start;
    --finish;
    vector<vector<pair<ll, ll>>> a(n);
    vector<ll> dis1(n, inf);
    vector<ll> dis2(n, inf);
    for(i=0;i<m;++i){
        cin>>x>>y>>w;
        --x;
        --y;
        a[x].pb({y, w});
        a[y].pb({x, w});
    }
    Dijkstra(start, a, dis1);
    Dijkstra(finish, a, dis2);
    if(dis1[finish] <= k){
        cout<<n*(n-1)/2<<endl;
        return;
    }
    sort(dis1);
    sort(dis2);
    k -= l;
    for(i=0;i<n;++i){
        res += upper_bound(dis2.begin(), dis2.end(), k - dis1[i]) - dis2.begin();
    }
    cout<<res<<endl;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    srand(time(nullptr));
    ll t=1;
//    cin>>t;
    for(;t>0;--t){
        solve();
    }
    return 0;
}

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