@[Channel_09](https://www.luogu.com.cn/user/787888)
有4个错误：
1.flag数组不用开
2.if (a < b && b < c)判断部分记忆数组sum要等于这个递归函数的运算：
```
return sum[a][b][c] = W(a,b,c - 1) + W(a,b - 1,c - 1) - W(a,b - 1,c);
```
```
return sum[a][b][c] = W(a - 1,b,c - 1) + W(a - 1,b - 1,c) + W(a - 1,b,c) - W(a - 1,b - 1,c - 1);
```
3.为了防止多次调用滥用时间，判断sum是否有数，有数输出，无数存起来
4.输出错了：
```
cout<<"w("<<u<<", "<<v<<", "<<w<<") = "<<W(u,v,w)<<endl;
```
## 下面是改的代码：
------------
```
#include <iostream>
using namespace std;
long long sum[100][100][100] = { 0 };
long long W(long long a, long long b, long long c)
{
if (a <= 0 || b <= 0 || c <= 0)
{
return 1;
}
else if (a > 20 || b > 20 || c > 20)
{
return W(20, 20, 20);
}if(sum[a][b][c] > 0) return sum[a][b][c];
else if (a < b && b < c)
{
return sum[a][b][c] = W(a,b,c - 1) + W(a,b - 1,c - 1) - W(a,b - 1,c);
}
else
{
return sum[a][b][c] = W(a - 1,b,c - 1) + W(a - 1,b - 1,c) + W(a - 1,b,c) - W(a - 1,b - 1,c - 1);
}
}
int main()
{
while (true)
{
long long u, v, w;
cin >> u >> v >> w;
if (u == -1 && v == -1 && w == -1)
{
break;
}
cout<<"w("<<u<<", "<<v<<", "<<w<<") = "<<W(u,v,w)<<endl;
}
return 0;
}
```
by Chicken_cooked_fish @ 2024-06-10 14:13:12
中间if (a < b && b < c)太复杂了，我精简了一下
by Chicken_cooked_fish @ 2024-06-10 14:14:20
@[Chicken_cooked_fish](/user/1043998) 谢谢大犇帮忙！
orz
by Channel_Choo @ 2024-06-10 15:34:09
@[Chicken_cooked_fish](/user/1043998) 没RE了，但WA,样例也是能过得
by Channel_Choo @ 2024-06-10 15:55:55
@[Channel_09](/user/787888) 输出错了
by Chicken_cooked_fish @ 2024-06-10 16:14:16
```
cout<<"w("<<u<<", "<<v<<", "<<w<<") = "<<W(u,v,w)<<endl;
```
,后面有空格
by Chicken_cooked_fish @ 2024-06-10 16:14:57
@[Channel_09](/user/787888)
by Chicken_cooked_fish @ 2024-07-08 18:00:38
输出错了
by Chicken_cooked_fish @ 2024-07-08 18:01:02