Cod sursa(job #1705114)

Utilizator kittDenisa kitt Data 19 mai 2016 22:47:39
Problema Algoritmul lui Dijkstra Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 1.35 kb
#include <stdio.h>
#include <vector>
#include <algorithm>
#include <queue>

#define NMAX 50001
#define MMAX 250001
#define INF 99999

using namespace std;

class mycomparison
{
  bool reverse;
public:
  bool operator() (const pair<int, int>& lhs, const pair<int, int>&rhs) const
  {
	 return lhs.second > rhs.second;
  }
};
priority_queue <pair <int, int>, vector<pair <int,int> >, mycomparison > q;
vector<pair<int, int> > adjList[NMAX];
int dist[NMAX], previous[NMAX];
int n, m;

void dijkstra(int source) {
	for (int i = 2; i <= n; ++i) {
		dist[i] = INF;
		previous[i] = -1;
		q.push(make_pair(i, dist[i]));
	}
	previous[source] = -1;
	dist[source] = 0;
	q.push(make_pair(source, dist[source]));
	while(!q.empty()) {
		pair<int, int> nod = q.top();
		q.pop();
		for (int i = 0; i < adjList[nod.first].size(); ++i) {
			int alt = dist[nod.first] + adjList[nod.first][i].second;
			if (alt < dist[adjList[nod.first][i].first]) {
				dist[adjList[nod.first][i].first] = alt;
				previous[adjList[nod.first][i].first] = nod.first;
			}
		}
	}
}

int main() {
	FILE *in, *out;
	in = fopen("dijkstra.in", "r");
	out = fopen("dijkstra.out", "w");
	int a, b, l;
	fscanf(in, "%d%d", &n, &m);
	for (int i = 1; i <= m; ++i) {
		fscanf(in, "%d%d%d", &a, &b, &l);
		adjList[a].push_back(make_pair(b, l));
	}
	dijkstra(1);
	for (int i = 2; i <= n; ++i) {
		fprintf(out, "%d ", dist[i]);
	}
}