1 1 1 2 2 2 10 4 6 50 50 50 -1 7 18 -1 -1 -1
w(1, 1, 1) = 2 w(2, 2, 2) = 4 w(10, 4, 6) = 523 w(50, 50, 50) = 1048576 w(-1, 7, 18) = 1
#include <cstdio>
#include <cstring>
int const MAX = 60;
int dp[MAX][MAX][MAX];
int DFS(int a, int b, int c)
{
if(a <= 0 || b <= 0 || c <= 0)
return 1;
if(dp[a][b][c])
return dp[a][b][c];
if(a < b && b < c)
return dp[a][b][c] = DFS(a, b, c - 1) + DFS(a, b - 1, c - 1) - DFS(a, b - 1, c);
else
return dp[a][b][c] = DFS(a - 1, b, c) + DFS(a - 1, b - 1, c) + DFS(a - 1, b, c - 1) - DFS(a - 1, b - 1, c - 1);
}
int main()
{
int a, b, c;
while(scanf("%d %d %d", &a, &b, &c) != EOF)
{
if(a == -1 && b == -1 && c == -1)
break;
if(a <= 0 || b <= 0 || c <= 0)
{
printf("w(%d, %d, %d) = 1\n", a, b, c);
continue;
}
if(a > 20 || b > 20 || c > 20)
{
printf("w(%d, %d, %d) = %d\n", a, b, c, DFS(20, 20, 20));
continue;
}
printf("w(%d, %d, %d) = %d\n", a, b, c, DFS(a, b, c));
}
}HDU 1331 Function Run Fun (基础记忆化搜索)
原文地址：http://blog.csdn.net/tc_to_top/article/details/45222579
