@[陆小果](/space/show?uid=113932) 等等这题不是求最大值吗。。
by 1saunoya @ 2019-09-27 12:20:38
`ans = max(ans,a[i].w)`
by 1saunoya @ 2019-09-27 12:21:01
@[清风ღ](/space/show?uid=96580)
因为我之前排过序了，所以后面的一定更大，直接赋值就行了.....
by lxg_honoka @ 2019-09-27 17:33:52
为啥你find了两次
by 1saunoya @ 2019-09-27 17:34:49
@[陆小果](/space/show?uid=113932)
by 1saunoya @ 2019-09-27 17:34:52
@[清风ღ](/space/show?uid=96580)
好像不影响结果叭...
by lxg_honoka @ 2019-09-27 17:36:53
```
for (int i = 1; i <= m; i++)
{
int x = find(a[i].u), y = find(a[i].v);
if (x != y)
{
ans = a[i].w;
unionset(a[i].u, a[i].v);
}// here
}
by 1saunoya @ 2019-09-27 17:37:53
@[陆小果](/space/show?uid=113932)
by 1saunoya @ 2019-09-27 17:37:57
呃，改了一下，然后还是10分...QAQ
我最看不懂的是RE....
```cpp
#include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;
const int maxn = 40000 + 10;
int fa[4000 + 10];
int n, m, ans = -1;
struct stu
{
int u, v, w;
}a[maxn];
bool cmp (stu a, stu b)
{
return a.w < b.w;
}
int read()
{
int c, s = 0;
c = getchar();
while (c < '0' || c > '9') c = getchar();
while (c >= '0' && c < '9')
{
s *= 10;
s += c - '0';
c = getchar();
}
return s;
}
void makeset (int size)
{
for (int i = 1; i <= size; i++)
fa[i] = i;
return;
}
int find (int x)
{
if (fa[x] != x)
fa[x] = find(fa[x]);
return fa[x];
}
/*
void unionset (int x, int y)
{
x = find(x), y = find(y);
if (x == y)
return;
fa[x] = y;
}
*/
void kruskal ()
{
makeset(n);
sort(a+1, a+m+1, cmp);
for (int i = 1; i <= m; i++)
{
int x = find(a[i].u), y = find(a[i].v);
if (x != y)
{
ans = a[i].w;
fa[x] = y;
}
}
}
int main()
{
n = read(), m = read();
for (int i = 1; i <= m; i++)
{
a[i].u = read();
a[i].v = read();
a[i].w = read();
}
kruskal();
printf("%d\n", ans);
return 0;
}
```
by lxg_honoka @ 2019-09-27 17:42:14
我查出了哪错了...
快读那里
```cpp
while (c >= '0' && c < '9')
{
s *= 10;
s += c - '0';
c = getchar();
}
```
少写了一个等号 Orz
非常感谢您帮我查错QAQ
by lxg_honoka @ 2019-09-27 18:10:59