POJ1579 Function Run Fun

 1 /*
 2 @author: Lev
 3 @date:
 4 */
 5 #include <iostream>
 6 #include <cstdio>
 7 #include <cmath>
 8 #include <cstring>
 9 #include <string>
10 #include <cstdlib>
11 #include <algorithm>
12 #include <map>
13 #include <set>
14 #include <queue>
15 #include <climits>
16 #include <deque>
17 #include <sstream>
18 #include <fstream>
19 #include <bitset>
20 #include <iomanip>
21 #define LL long long
22 #define PI acos(-1)
23 using namespace std;
24 int dp[30][30][30];
25 int go(int a,int b,int c) {
26     if(a <= 0 || b <= 0 || c <= 0) return 1;
27     if(a > 20 || b > 20 || c > 20) return go(20,20,20);
28     if(dp[a][b][c]) return dp[a][b][c];
29     if(a < b && b < c) dp[a][b][c] = go(a,b,c-1)+go(a,b-1,c-1)-go(a,b-1,c);
30     else dp[a][b][c] = go(a-1, b, c) + go(a-1, b-1, c) + go(a-1, b, c-1) - go(a-1, b-1, c-1);
31     return dp[a][b][c];
32 }
33 int main() {
34     memset(dp,0,sizeof(dp));
35     int a,b,c;
36     while(~scanf("%d %d %d",&a,&b,&c)) {
37         if(a == -1 && b == -1 && c == -1) break;
38         printf("w(%d, %d, %d) = %d\n",a,b,c,go(a,b,c));
39     }
40     return 0;
41 }