Cod sursa(job #1049189)

Utilizator Athena99Anghel Anca Athena99 Data 7 decembrie 2013 00:04:04
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 1.47 kb
#include <fstream>
#include <queue>
#include <vector>

using namespace std;

ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");

const int inf= 1<<30;
const int nmax= 50000;

struct str {
    int x, y;
};
vector <str> v[nmax+1];

struct str_cmp {
    bool operator() ( const str &x, const str &y ) {
        if ( x.x==y.x ) {
            return x.y>y.y;
        } else {
            return x.x>y.x;
        }
    }
};

priority_queue <str, vector <str>, str_cmp> q;

inline str mp ( int x, int y ) {
    str sol;
    sol.x= x;
    sol.y= y;
    return sol;
}

int d[nmax+1];
bool u[nmax+1];

void dijkstra(  ) {
    q.push(mp(1,0));
    while ( !q.empty() ) {
        str x;
        x= q.top();
        q.pop();
        if ( u[x.x]==1 ) {
            continue;
        }
        u[x.x]= 1;
        for ( int i= 0; i<(int)v[x.x].size(); ++i ) {
            if ( d[x.x]+v[x.x][i].y<d[v[x.x][i].x] ) {
                d[v[x.x][i].x]= d[x.x]+v[x.x][i].y;
                if ( u[v[x.x][i].x]==0 ) {
                    q.push(mp(v[x.x][i].x, d[v[x.x][i].x] ));
                }
            }
        }
    }
}

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

    for ( int i= 2; i<=n; ++i ) {
        d[i]= inf;
    }

    for ( ; m>0; --m ) {
        int a, b, c;
        fin>>a>>b>>c;
        v[a].push_back(mp(b, c));
    }

    dijkstra();

    for ( int i= 2; i<=n; ++i ) {
        if ( d[i]==inf ) {
            d[i]= 0;
        }
        fout<<d[i]<<" ";
    }
    fout<<"\n";

    return 0;
}