Cod sursa(job #3166488)

Utilizator maiaauUngureanu Maia maiaau Data 8 noiembrie 2023 20:10:04
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.88 kb
#include <bits/stdc++.h>
using namespace std;
using pii = pair<int,int>;
#define fi first
#define se second
#define pb push_back

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

const int N = 5e4+3;
const int oo = 0x3f3f3f3f;

int n;
vector<vector<pii>> e;
vector<int> cnt, cst;
void read(), dijkstra();

int main()
{
	read(); 
	dijkstra();
	for (int i = 2; i <= n; i++) g << cst[i] << ' ';

	return 0;
}

void read(){
	int m;
	f >> n >> m; 
	e.resize(n+3); cnt.resize(n+3); cst.resize(n+3, oo);
	while (m--){
		int a, b, c; f >> a >> b >> c;
		e[a].pb({b,c});
	}
}
void dijkstra(){
	set<pii> s; s.insert({0, 1});
	while (!s.empty()){
		int from, c; 
		tie(c,from) = *s.begin(); s.erase(s.begin());
		for (auto it: e[from]){
			int to, cm; tie(to, cm) = it;
			if (cm + c < cst[to]){
				if (cst[to] != oo) s.erase({cst[to], to});
				cst[to] = c + cm;
				s.insert({cst[to], to});
			}
		}
	}
}