Cod sursa(job #886149)

Utilizator anca1243Popescu Anca anca1243 Data 22 februarie 2013 17:50:20
Problema Distante Scor 0
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.53 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream in("distante.in");
ofstream out("distante.out");
struct cost
{
    int vf,c;
};
const int N=50001,INF=500000000;
vector <cost> a[N];
queue <int> q;
int n,m,s,t,d[N],d1[N];
bool inq[N];
void citire()
{
    int x,y,c;
    cost aux;
    in>>n>>m>>s;
    for(int i=1;i<=n;i++)
        in>>d1[i];
    for(int i=1;i<=m;i++)
    {
        in>>x>>y>>c;
        aux.vf=y;
        aux.c=c;
        a[x].push_back(aux);
        aux.vf=x;
        a[y].push_back(aux);
    }
}
bool bfs(int x)
{
    int y;
    q.push(x);
    while(!q.empty())
    {
        x=q.front();
        q.pop();
        inq[x]=false;
        for(size_t i=0;i<a[x].size();i++)
        {
            y=a[x][i].vf;
            if(d[y]>=d[x]+a[x][i].c)
            {

                d[y]=d[x]+a[x][i].c;
                if(!inq[y])
                {
                    q.push(y);
                    inq[y]=true;
                }
            }
            if(d[y]!=d1[y])
                return false;
        }
    }
    return true;
}
void init()
{
    for(int i=0;i<=N;i++)
    {
        a[i].clear();
        inq[i]=false;
    }
}
int main()
{
    int ok=1;
    in>>t;
    for(int i=1;i<=t;i++)
    {
        init();
        citire();
        for(int j=1;j<=n;j++)
            d[j]=INF;
        d[s]=0;
        if(bfs(s))
            out<<"DA"<<'\n';
        else
            out<<"NU"<<'\n';
    }
    return 0;
}