@[某幻上野花](/user/406817) 不开ULL见祖宗
by jaco2559 @ 2022-02-18 21:06:44
您的 int 貌似爆炸了
by Avocadooo @ 2022-02-18 21:08:15
@[jaco2559](/user/329306) 巨佬!!那这个呢,只有82(哭
```cpp
#include <bits/stdc++.h>
using namespace std;
int main()
{
unsigned long long n,a,b,c;
scanf("%lld",&n);
b=4*3*2*1;
a=n*(n-1)*(n-2)*(n-3);
c=a/b;
printf("%lld",c);
return 0;
}
```
by Daaaaaaazai @ 2022-02-18 21:10:00
@[某幻上野花](/user/406817) **%lld**
by jaco2559 @ 2022-02-18 21:11:20
@[乔木生夏凉](/user/432127) 阿里嘎多!!!
by Daaaaaaazai @ 2022-02-18 21:11:28
@[jaco2559](/user/329306) 嘶...抱歉,不太明白
by Daaaaaaazai @ 2022-02-18 21:12:35
建议不要堆到一块除,可以先算一部分除了之后再乘
by Avocadooo @ 2022-02-18 21:13:00
```n*(n-1)/2*(n-2)/3*(n-3)/4```
by Avocadooo @ 2022-02-18 21:13:54
@[乔木生夏凉](/user/432127) 但是为什么这种不会爆掉,之前那种会爆掉啊...
by Daaaaaaazai @ 2022-02-18 21:23:09
额数据范围是 $ 10^5 $ ,在```unsigned long long``` 下好像最高是 $ 10^{19} $ ,你要计算 $ n(n-1)(n-2)(n-3) $ 应该是会爆的(或许是吧
by Avocadooo @ 2022-02-18 21:25:05