POJ 1579
地址:http://poj.org/problem?id=1579
题意:按照题目要求递归。
mark:直接递归肯定是TLE的。记忆化深度搜索。
代码:
#include <stdio.h> int s[21][21][21]; 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 s[20][20][20] = w(20, 20, 20); if(s[a][b][c]) return s[a][b][c]; if(a < b && b < c) return s[a][b][c] = w(a, b, c-1) + w(a, b-1, c-1) - w(a, b-1, c); return s[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); } int main() { int a,b,c; while(scanf("%d%d%d", &a, &b, &c), (a+1 || b+1 || c+1)) printf("w(%d, %d, %d) = %d\n", a, b, c, w(a, b, c)); return 0; }