Cod sursa(job #1010854)

Utilizator assa98Andrei Stanciu assa98 Data 15 octombrie 2013 20:17:31
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.53 kb
#include <cstdio>
#include <algorithm>
#include <queue>
using namespace std;

struct pereche {
    int a,b;
    pereche() {
        a=b=0;
    }
    pereche(int x,int y) {
        a=x;
        b=y;
    }
};

class cmp {
public:
    inline bool operator() (const pereche &a,const pereche &b) {
        return a.b>b.b;
    }
};

const int MAX_N=50100;
const int INF=1000000000;   

vector<pereche> A[MAX_N];

priority_queue<pereche,vector<pereche>,cmp> Q;

int viz[MAX_N];
int dmin[MAX_N];

void dijkstra() {
    dmin[1]=0;
    Q.push(pereche(1,0));
    
    while(!Q.empty() ) {
        int nod=Q.top().a;
        int cst=Q.top().b;
       
        viz[nod]=1;
        Q.pop();
        for(vector<pereche>::iterator it=A[nod].begin();it!=A[nod].end();it++) {
            if(!viz[it->a]) {
                if(dmin[it->a]>cst+it->b) {
                    dmin[it->a]=cst+it->b;
                    Q.push(pereche(it->a,dmin[it->a]));
                }
            }
        }

        while(!Q.empty()&&viz[Q.top().a]) {
            Q.pop();
        }
    }
}

int main() {
    freopen("dijkstra.in","r",stdin);
    freopen("dijkstra.out","w",stdout);
    int n,m;
    scanf("%d%d",&n,&m);
    for(int i=1;i<=m;i++) {
        int a,b,c;
        scanf("%d%d%d",&a,&b,&c);
        A[a].push_back(pereche(b,c));
    }
    
    for(int i=1;i<=n;i++) {
        dmin[i]=INF;
    }
    dijkstra();

    for(int i=2;i<=n;i++) {
        if(dmin[i]==INF) {
            printf("0 ");
        }
        else {
            printf("%d ",dmin[i]);
        }
    }

    return 0;
}