AtCoder Beginner Contest 079 D - Wall【Warshall Floyd algorithm】

AtCoder Beginner Contest 079 D - Wall

Warshall Floyd 最短路。。。。先枚举 k

 #include<iostream>
 #include<cstdio>
 #include<cstring>
 #include<algorithm>
 using namespace std;
 int c[][];
 int H, W, A, ans;

 int main()
 {
     scanf("%d%d", &H, &W);
     for (int i = ; i < ; i++)
         for (int j = ; j < ; j++)
             scanf("%d", &c[i][j]);
     for(int k=;k<;k++)
         for(int i=;i<;i++)
             for (int j = ; j < ; j++) {
                 if (c[i][j] > c[i][k] + c[k][j])
                     c[i][j] = c[i][k] + c[k][j];
             }
     ans = ;
     for(int i=;i<H;i++)
         for (int j = ; j < W; j++) {
             scanf("%d", &A);
             if (A >= )
                 ans += c[A][];
         }
     printf("%d\n", ans);
     return ;
 }