@[qhcKing](/user/775011)
```cpp
#include <bits/stdc++.h>
using namespace std;
#define ll long long
ll rem[21][21][21];
bool vis[21][21][21];
ll w(ll a,ll b,ll c){
if(a<=0||b<=0||c<=0) return 1;
if(a>20||b>20||c>20) return w(20,20,20);
if(vis[a][b][c]) return rem[a][b][c];
if(a<b&&b<c) rem[a][b][c]=w(a,b,c-1)+w(a,b-1,c-1)-w(a,b-1,c);
else rem[a][b][c]=w(a-1,b,c)+w(a-1,b-1,c)+w(a-1,b,c-1)-w(a-1,b-1,c-1);
vis[a][b][c]=1;
return rem[a][b][c];
}
int main(){
while(1){
ll a,b,c;
cin>>a>>b>>c;
if(a==-1&&b==-1&&c==-1) break;
cout<<"w("<<a<<", "<<b<<", "<<c<<')'<<" = "<<w(a,b,c)<<endl;
}
return 0;
}
```
式子写错了。看了挺久。
by Faith_toChange @ 2024-08-04 17:02:48
@[Faith_toChange](/user/374769)
已AC，感谢大佬，已关
by qhcKing @ 2024-08-04 17:23:37