题目链接：点击打开链接
题意很简单，记忆化搜索的水题......
// POJ 1579 Function Run Fun.cpp #include <cstdio> #include <cstring> #include <algorithm> #include <iostream> using namespace std; int dp[25][25][25]; int dfs(int a, int b, int c) { if (a <= 0 || b <= 0 || c <= 0) { return 1; } if (a > 20 || b > 20 || c > 20) { return dfs(20, 20, 20); } if (dp[a][b][c] != -1) { return dp[a][b][c]; } else if (a < b && b < c) { dp[a][b][c] = dfs(a, b, c - 1) + dfs(a, b - 1, c - 1) - dfs(a, b - 1, c); return dp[a][b][c]; } else { 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); return dp[a][b][c]; } } int main(){ int a, b, c; memset(dp, -1, sizeof(dp)); while (scanf("%d%d%d", &a, &b, &c) != EOF) { if (a == -1 && b == -1 && c == -1) { break; } printf("w(%d, %d, %d) = %d\n", a, b, c, dfs(a, b, c)); } return 0; }
