Cod sursa(job #1486333)

Utilizator serbanSlincu Serban serban Data 14 septembrie 2015 18:17:14
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 2.08 kb
#include <bits/stdc++.h>

using namespace std;

struct graph{
    graph *next;
    int to;
    int length;
};

graph *e[50005];

bool v[50005];
int d[50005];

deque<pair<int, int>> q;

int main()
{
    FILE *f = fopen("dijkstra.in", "r");
    FILE *g = fopen("dijkstra.out", "w");

    int n, m;
    fscanf(f, "%d %d", &n, &m);
    for(int i = 1; i <= m; i ++) {
        int a, b, c;
        fscanf(f, "%d %d %d", &a, &b, &c);
        graph *one = new graph;
        one->to = b;
        one->length = c;
        one->next = e[a];
        e[a] = one;
    }

    for(int i = 2; i <= n; i ++)
        d[i] = 50000000;
    v[1] = true;

    q.push_back(make_pair(1, 0));
    while(!q.empty()) {
        int i = q.front().first;
        d[i] = q.front().second;
        q.pop_front();
        graph *cur = e[i];
        while(cur != NULL) {
            int pos = 0;
            int mn = 50000001;
            while(cur != NULL) {
                if(cur->length < mn) {
                    mn = cur->length;
                    pos = cur->to;
                }
                cur = cur->next;
            }
            cur = e[i];
            graph *past = NULL;
            graph *ret = cur;
            while(cur != NULL) {
                if(cur->length == mn && cur->to == pos) {
                    graph *del = cur;
                    cur = cur->next;
                    if(past != NULL)
                        past->next = cur;
                    else
                        ret = cur;
                    delete(del);
                }
                if(cur != NULL) {
                    past = cur;
                    cur = cur->next;
                }
            }
            e[i] = ret;
            if(!v[pos] || d[pos] > d[i] + mn) {
                d[pos] = d[i] + mn;
                v[pos] = true;
                q.push_back(make_pair(pos, d[i] + mn));
            }
            cur = e[i];
        }
    }

    for(int i = 2; i <= n; i ++) {
        fprintf(g, "%d ", d[i]);
    }
    fprintf(g, "\n");
    return 0;
}