hihoCoder#1089 最短路径·二：Floyd算法

原题地址

 

感觉Floyd算法比Dijkstra还要简单。。

唯一需要注意的是，初始的距离默认值不要设过大，否则溢出就不好了，根据题意，只要大于10^3即可

 

代码：

 1 #include 
 2 #include 
 3 
 4 using namespace std;
 5 
 6 #define MAX_POINT 1024
 7 #define MAX_EDGE 16384
 8 
 9 int N, M;
10 int d[MAX_POINT][MAX_POINT];
11 
12 void floyd() {
13   for (int k = 1; k <= N; k++) {
14     for (int i = 1; i <= N; i++) {
15       for (int j = 1; j <= N; j++) {
16         if (k == i || i == j || j == k)
17           continue;
18         d[i][j] = min(d[i][j], d[i][k] + d[k][j]);
19       }
20     }
21   }
22 }
23 
24 int main() {
25   memset(d, 1, sizeof(d));
26   scanf("%d%d", &N, &M);
27   for (int i = 1; i <= N; i++)
28     d[i][i] = 0;
29   for (int i = 0; i < M; i++) {
30     int a, b, len;
31     scanf("%d%d%d", &a, &b, &len);
32     d[a][b] = d[b][a] = min(d[a][b], len);
33   }
34 
35   floyd();
36 
37   for (int i = 1; i <= N; i++) {
38     for (int j = 1; j < N; j++)
39       printf("%d ", d[i][j]);
40     printf("%d\n", d[i][N]);
41   }
42   return 0;
43 }

 

转载于:https://www.cnblogs.com/boring09/p/4396505.html