Cod sursa(job #2976136)

Utilizator maiaauUngureanu Maia maiaau Data 8 februarie 2023 13:41:15
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.21 kb
#include <bits/stdc++.h>
using namespace std;

ifstream f("dijkstra.in");
ofstream g("dijkstra.out");

#define pb push_back

const int N = 5e4 + 5;
const int oo = 0x3f3f3f3f;

int n, m, cmin[N];
multiset<pair<int, int>> h;
vector<pair<int, int>> v[N];

void read(), dijkstra();
inline void prt();

int main()
{
    read();
    memset(cmin, oo, sizeof cmin);
    cmin[1] = 0; h.insert({0, 1});
    dijkstra();
    prt();

    return 0;
}

void read(){
    int a, b, c;
    f >> n >> m;
    for (; m; m--){
        f >> a >> b >> c;
        v[a].pb({b, c});
    }
}
inline void prt(){
    for (int i = 2; i <= n; i++)
        if (cmin[i] == oo) g << 0 << ' ';
        else g << cmin[i] << ' ';
}
void dijkstra(){
    while (!h.empty()){
        int nod, cost;
        nod = h.begin()->second; cost = h.begin()->first;
        //tie(cost, nod) = h.begin();
        h.erase(h.begin());
        for (auto it: v[nod]){
            int x, cm; tie(x, cm) = it;
            if (cost + cm < cmin[x]){
                if (cmin[x] != oo)
                    h.erase({cmin[x], x});
                cmin[x] = cost + cm;
                h.insert({cmin[x], x});

            }
        }
    }
}