1 #include<stdio.h> 2 #include<queue> 3 4 using namespace std; 5 static const int N = 100; 6 static const int INFTY = (1 << 21); 7 8 int n, M[N][N]; 9 int d[N]; 10 11 void bfs(int s) 12 { 13 queue<int> q; 14 q.push(s); 15 for (int i = 0;i < n;i++ ) d[i] = INFTY; 16 d[s] = 0; //将第一个节点的距离定义为 0 17 int u; 18 while( !q.empty() ) { //如果队列不为空 19 u = q.front() ; q.pop() ; //将队首取出 20 for ( int v = 0; v < n;v++ ){ 21 if ( M[u][v] == 0 || d[v] != INFTY) continue; //M为领接矩阵判断是否连通，d判断是否已遍历过 22 d[v] = d[u] + 1; //d[u]为前一步的距离 23 q.push(v); //将新的节点放入队列 24 } 25 } 26 }