题目传送门
解题思路:
跑Kruskal,直到s与t联通,输出最大值
AC代码:
1 #include<cstdio> 2 #include<iostream> 3 #include<algorithm> 4 5 using namespace std; 6 7 int n,m,s,t,fa[10001],ans; 8 struct kkk { 9 int from,to,v; 10 }e[20001]; 11 12 bool cmp(kkk a,kkk b) { 13 return a.v < b.v; 14 } 15 16 int find_father(int x) { 17 if(fa[x] == x) return x; 18 return fa[x] = find_father(fa[x]); 19 } 20 21 int main() 22 { 23 scanf("%d%d%d%d",&n,&m,&s,&t); 24 for(int i = 1;i <= n; i++) 25 fa[i] = i; 26 for(int i = 1;i <= m; i++) 27 scanf("%d%d%d",&e[i].from,&e[i].to,&e[i].v); 28 sort(e+1,e+m+1,cmp); 29 for(int i = 1;i <= m; i++) { 30 int x1 = find_father(e[i].from); 31 int y1 = find_father(e[i].to); 32 if(x1 != y1) { 33 fa[x1] = y1; 34 ans = max(ans,e[i].v); 35 } 36 if(find_father(s) == find_father(t)) { 37 printf("%d",ans); 38 return 0; 39 } 40 } 41 return 0; 42 }