专题四 · 1011

Posted 2023-02-03 suamfadmp

代码及解释

#include <algorithm>
#include <limits.h>
#include <stdio.h>
#include <string.h>

// 最后一道 ACM 题
// 死活 A 不过去
// 然后我就看了别人的代码 A 了
// _:(´°ω°`」 ∠):_

const int SIZE = 2000;

int T, S, D, n;
int map[SIZE][SIZE];
int vis[SIZE], cast[SIZE];
int s[SIZE], e[SIZE];

void Dijkstra() 
  int i, j, minn, pos = 0;
  memset(vis, 0, sizeof(vis));
  vis[0] = 1;
  for (i = 0; i <= n; i++)
    cast[i] = map[0][i];
  for (i = 1; i <= n; i++) 
    minn = INT_MAX;
    for (j = 1; j <= n; j++) 
      if (cast[j] < minn && !vis[j]) 
        pos = j;
        minn = cast[j];
      
    
    vis[pos] = 1;
    for (j = 1; j <= n; j++) 
      if (cast[pos] + map[pos][j] < cast[j] && !vis[j])
        cast[j] = cast[pos] + map[pos][j];
    
  


int main() 
  int i, j, x, y, z;
  while (~scanf("%d%d%d", &T, &S, &D)) 
    n = 0;
    for (i = 0; i < SIZE; i++) 
      for (j = 0; j < SIZE; j++)
        map[i][j] = INT_MAX;
      map[i][i] = 0;
    
    while (T--) 
      scanf("%d%d%d", &x, &y, &z);
      n = std::max(std::max(n, x), y);
      if (z < map[x][y])
        map[x][y] = map[y][x] = z;
    
    int minn = INT_MAX;
    for (i = 0; i < S; i++) 
      scanf("%d", &s[i]);
      map[0][s[i]] = map[s[i]][0] = 0;
    
    for (i = 0; i < D; i++)
      scanf("%d", &e[i]);
    Dijkstra();
    for (i = 0; i < D; i++)
      minn = std::min(minn, cast[e[i]]);
    printf("%d\\n", minn);
  

  return 0;