这道题目不是纯模拟吧= =
by _FILARET_ @ 2018-09-24 09:55:52
你还得加记忆化才能保证不超时
by _FILARET_ @ 2018-09-24 09:56:43
用时6000ms 太厉害了
by wxy_god @ 2018-09-24 10:03:04
@[XZRY520](/space/show?uid=77584)
纯模拟是绝对不行的 这是我的记忆化搜索 因该能看懂（其实跟您的差不多）
```
#include <cstdio>
using namespace std;
long long f[21][21][21];
long long w (int a, int b, int c) {
if (a <= 0 || b <= 0 || c <= 0)
return 1;
if (a > 20 || b > 20 || c > 20)
return w(20, 20 , 20);
if (f[a][b][c] == 0)
{
if (a < b && b < c)
f[a][b][c] = w(a, b, c - 1) + w(a, b-1, c-1)-w(a, b-1, c);
else
f[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);
return f[a][b][c];
}
}
int main()
{
long long a, b, c;
while (true)
{
scanf ("%lld%lld%lld", &a, &b, &c);
if (a == -1 && b == -1 && c == -1)
break;
printf ("w(%lld, %lld, %lld) = %lld\n", a, b, c, w(a, b, c));
}
}
```
by wxy_god @ 2018-09-24 10:04:31