编写算法,判断图中顶点A和顶点B之间是否有边#include int main(){int a,b;int i,j;int n,m;scanf("%d%d",&a,&b);scanf("%d%d",&n,&m);while(m){scanf("%d%d",&i,&j);if((i==a&&j==b)||(i==b&&j==a))break;m--;}if(m>...