POJ_2394_最短路径---SPFA算法

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//============================================================================
// Name        : POJ_2394.cpp
// Author      : tiger
// Version     :
// Copyright   : Your copyright notice
// Description : 最短路径---SPFA算法
//============================================================================

#include <iostream>
#include <cstdio>
#include <queue>
using namespace std;
const int MAXN = 501;
const int inf = 100000000;
int mat[MAXN][MAXN];
bool v[MAXN];
int dist[MAXN];
void spfa(int s,int n)
{
queue<int> q;
q.push(s);
v[s] = true;
dist[s] = 0;
int t,i;
while (!q.empty())
{
  t = q.front();
  q.pop();
  v[t] = false;
  for (i = 0; i < n; i++)
  {
   if (dist[t] + mat[t][i] < dist[i])
   {
    dist[i] = dist[t] + mat[t][i];
    if (!v[i])
    {
     v[i] = true;
     q.push(i);
    }
   }

}
}

}
int main()
{
freopen("in", "r", stdin);
int F, P, C, M;
int i, j, k, sum, a, b;
int cows[101];
scanf("%d %d %d %d", &F, &P, &C, &M);
for (i = 0; i < F; i++)
{
  for (j = 0; j < F; j++)
   mat[i][j] = inf;
  mat[i][i] = 0;
  v[i] = false;
  dist[i] = inf;
}
for (i = 0; i < P; i++)
{
  scanf("%d %d %d", &a, &b, &k);
  a--;
  b--;
  if (k < mat[a][b])
  {
   mat[a][b] = k;
   mat[b][a] = k;
  }
}
spfa(0,F);
sum = 0;
for(i = 0; i < C; i++)
{
  scanf("%d",cows + i);
  if(dist[cows[i]-1] <= M )
   {
    sum++;
    cows[i] = 1;
   }
  else
   cows[i] = 0;
}
printf("%d/n",sum);
for(i = 0; i < C; i++)
{
  if(cows[i])
   printf("%d/n",i+1);
}

return 0;
}