Cod sursa(job #1714774)

Utilizator Alexghita96Ghita Alexandru Alexghita96 Data 9 iunie 2016 13:18:20
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.34 kb
#include <cstdio>
#include <vector>
#include <queue>
#include <cstring>

#define NMAX 50005
#define INF 0x3F3F3F3F

using namespace std;

int N, M, cost[NMAX];
vector <pair <int, int> > graph[NMAX];

void read() {
    int x, y, c;

    scanf("%d %d", &N, &M);

    for (int i = 1; i <= M; ++i) {
        scanf("%d %d %d", &x, &y, &c);
        graph[x].push_back(make_pair(c, y));
    }

    memset(cost, INF, sizeof(cost));
}

void dijkstra(int root) {
    priority_queue <pair <int, int> > q;
    vector <pair <int, int> > :: iterator it;
    int node;

    q.push(make_pair(0, root));
    cost[root] = 0;

    while (!q.empty()) {
        node = q.top().second;
        q.pop();

        for (it = graph[node].begin(); it != graph[node].end(); ++it) {
            if (cost[it -> second] > cost[node] + it -> first) {
                cost[it -> second] = cost[node] + it -> first;
                q.push(make_pair(-cost[it -> second], it -> second));
            }
        }
    }
}

void print() {
    for (int i = 2; i <= N; ++i) {
        if (cost[i] == INF) {
            printf("0 ");
        }
        else {
            printf("%d ", cost[i]);
        }
    }
}

int main() {
    freopen("dijkstra.in", "r", stdin);
    freopen("dijkstra.out", "w", stdout);

    read();
    dijkstra(1);
    print();
}