@[IaLWH](/user/486727) 你这个要用记忆化，单纯去递归会超时。我给你写一下代码
by zhuyucheng6046 @ 2024-08-07 16:01:55
@[zhuyucheng6046](/user/1312199) 我只是想知道为什么样例都会超时
by IaLWH @ 2024-08-07 16:03:48
你用 scanf 输入 long long 不应该用 %lld 吗?
by Gcc_Gdb_7_8_1 @ 2024-08-07 16:06:39
改完后就 AC 样例了
by Gcc_Gdb_7_8_1 @ 2024-08-07 16:07:55
@[IaLWH](/user/486727)
单纯递归会有许多重复计算，才会TLE;
用记忆化呢减少计算量
by xujiacheng0312 @ 2024-08-07 16:08:21
要不要 AC Code?
by Gcc_Gdb_7_8_1 @ 2024-08-07 16:11:39
@[IaLWH](/user/486727) ?
by Gcc_Gdb_7_8_1 @ 2024-08-07 16:12:57
```cpp
#include<cstdio>
#define int long long
int f[25][25][25];
int w(int a,int b,int c){
if(a<=0||b<=0||c<=0)
return 1;
if(a>20||b>20||c>20)
return (f[20][20][20]?f[20][20][20]:f[20][20][20]=w(20,20,20));
if(!f[a-1][b][c]) f[a-1][b][c]=w(a-1,b,c);
if(!f[a-1][b-1][c]) f[a-1][b-1][c]=w(a-1,b-1,c);
if(!f[a-1][b][c-1]) f[a-1][b][c-1]=w(a-1,b,c-1);
if(!f[a-1][b-1][c-1]) f[a-1][b-1][c-1]=w(a-1,b-1,c-1);
return f[a-1][b][c]+f[a-1][b-1][c]+f[a-1][b][c-1]-f[a-1][b-1][c-1];
}
signed main(){
int i,a=0,b=0,c=0;
f[0][0][0]=1;
scanf("%lld%lld%lld",&a,&b,&c);
for(i=0;a!=-1||b!=-1||c!=-1;i++){
printf("w(%lld, %lld, %lld) = %lld\n",a,b,c,w(a,b,c));
scanf("%lld%lld%lld",&a,&b,&c);
}
return 0;
}
```
没开记忆化肯定炸
输入也有问题，是%lld而不是%d
by GrainRain25 @ 2024-08-07 16:15:57
@[GrainRain25](/user/592897) 对
by Gcc_Gdb_7_8_1 @ 2024-08-07 16:16:53
```cpp
#include<bits/stdc++.h>
using namespace std;
long long f[25][25][25];
long long p(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 p(20,20,20);
else if(f[a][b][c]!=0) return f[a][b][c];
else if(a<b&&b<c) f[a][b][c]=p(a,b,c-1)+p(a,b-1,c-1)-p(a,b-1,c);
else f[a][b][c]=p(a-1,b,c)+p(a-1,b-1,c)+p(a-1,b,c-1)-p(a-1,b-1,c-1);
return f[a][b][c];
}
int main()
{
while(1)
{long long q,w,e;
scanf("%lld %lld %lld",&q,&w,&e);
//cout<<q<<" "<<w<<" "<<e<<endl;
if((q==-1)&&(w==-1)&&(e==-1)) break;
printf("w(%lld, %lld, %lld) = %d\n", q,w,e, p(q,w,e));
}
return 0;
}
```
by zhuyucheng6046 @ 2024-08-07 16:18:22