join成花瓶了，反复加同一集合的点，最终没有全联通
input:
4 4
1 2 23
2 3 1000
1 3 43
1 4 9999
output:
1000
answer:
9999
改为:
```cpp
bool join(int c1, int c2) {
int f1 = find(c1), f2 = find(c2);
if (f1 != f2){
fa[f1] = f2;
return 0;
}
return 1;
}
```
```cpp
for (int i = 1; i <= m; i++) {
if(!join(e[i].s, e[i].t)){
if (e[i].w > maxn)
maxn = e[i].w;
ans++;
}
if (ans == n - 1) {
cout << maxn;
return 0;
}
}
```
by luo_xiaoran @ 2023-04-06 15:51:22
@[Lingyv_OIer](/user/727587)
by luo_xiaoran @ 2023-04-06 15:53:05
@[luo_xiaoran](/user/605945) thx
by HK_Merlin @ 2023-04-06 17:48:40