Cod sursa(job #2369809)

Utilizator StefanManolacheManolache Stefan StefanManolache Data 6 martie 2019 09:20:25
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 2.03 kb
#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <set>

FILE *fin = fopen("dijkstra.in", "r");
FILE *fout = fopen("dijkstra.out", "w");

#define MAXN 500000
#define INF 250000000000
std::vector <std::pair<int,int>> v[MAXN + 1];
std::multiset <std::pair<int, long long>> s;

bool viz[MAXN + 1];
int q[MAXN + 1];
int st =  0;
int dr = 0;
long long dist[MAXN + 1];

inline void add(int p) {
    dr++;
    q[dr] = p;
    viz[p] = 1;
}
inline void del() {
    st++;
}

/*void bfs(int a) {
    add(a);
    while (st <= dr) {
        int s = v[q[st]].size();
        for (int i = 0; i < s; i++) {
            if (viz[v[q[st]][i]] == 0) {
                add(v[q[st]][i]);
                dist[v[q[st]][i]] = dist[q[st]] + 1;
            }
        }
        del();
    }
}

void dfs(int i) {
    viz[i] = 1;
    int k = v[i].size();
    for (int j = 0; j < k; j++)
        if (viz[v[i][j]] == 0)
            dfs(v[i][j]);
}*/

int main()
{
    int m, n, x, y, c;
    fscanf(fin, "%d%d", &n, &m);
    for (int i = 1; i <= m; i++) {
        fscanf(fin, "%d%d%d", &x, &y, &c);
        v[x].push_back(std::make_pair(y,c));
    }
    dist[1] = 0;
    for (int i = 2; i <= n; i++) {
        dist[i] = INF;
    }
    s.insert(std::make_pair(1, dist[1]));
    while (s.empty() == 0) {
        int p = s.begin()->first;
        s.erase(s.begin());
        int siz = v[p].size();
        for (int i = 0; i < siz; i++) {
            y = v[p][i].first;
            c = v[p][i].second;
            if (dist[y] > dist[p] + c) {
                if (dist[y] != INF) {
                    s.erase(s.find(std::make_pair(y, dist[y])));
                }
                dist[y] = dist[p] + c;
                s.insert(std::make_pair(y, dist[y]));
            }
        }
    }
    for (int i = 2; i <= n; i++) {
        if (dist[i] == INF)
            fprintf(fout, "0");
        else
            fprintf(fout, "%lld", dist[i]);
        fprintf(fout, " ");
    }
    return 0;
}