Cod sursa(job #2198554)

Utilizator cristiP97Prodan Cristian cristiP97 Data 24 aprilie 2018 17:24:35
Problema Algoritmul Bellman-Ford Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 1.47 kb
#include <fstream>
#include <vector>
#include <algorithm>
#include <iostream>
#include <queue>

using namespace std;
ifstream in("bellmanford.in");

struct comp {
    bool operator()(pair <int, int> &a, pair <int, int> &b) {
        return a.second > b.second;
    }
};

const int knmax = 50005;
const int INF = 999999999;
vector <pair <int,int> > adj[knmax];
int d[knmax];
priority_queue<pair <int, int> ,vector <pair <int,int> >, comp> PQ;

void citire(int m){

    int nod1,nod2,cost;
    for(int i = 1; i<= m; ++i) {
        in >> nod1 >> nod2 >> cost;
        adj[nod1].push_back(make_pair(nod2,cost));
    }
}

int main() {
    int n,m;
    in >> n >> m;

    citire(m);
    in.close();

	for(int i = 1; i <= n; ++i) {
		d[i] = INF;
	}
	
	for(unsigned int i = 0; i < adj[1].size(); ++i) {
		d[adj[1][i].first] = adj[1][i].second;
	}
	
	d[1] = 0;
	
	//for(int i = 1; i < n; ++i) {
		for(int k = 1; k < n; ++k){
			for(unsigned int j = 0; j < adj[k].size(); ++j) {
				int cost = adj[k][j].second;
				int nod = adj[k][j].first;
						
				if(d[nod] > d[k] + cost) {
					d[nod] = d[k] + cost;
				}
			}
		}
		
	//}
	
	ofstream out ("bellmanford.out");
	
	for(int k = 1; k <= n; ++k){
		for(unsigned int j = 0; j < adj[k].size(); ++j) {
			int cost = adj[k][j].second;
			int nod = adj[k][j].first;
					
			if(d[nod] > d[k] + cost) {
				out << "Ciclu negativ!";
				return 0;
			}
		}
	}
    
    
    for(int i = 2; i <= n; ++i) {
		out << d[i] << " ";
	}
	
	out.close();
    
    
    return 0;
}