pku 2663 3*n铺地板问题

 #include <iostream> using namespace std; int v[31]; int n; int solve(int i) { if(i == 0) return 1; if(v[i]) return v[i]; v[i] += 3*solve(i-2); for(int k = 4; k <= i; k+=2) v[i] += 2*solve(i-k); return v[i]; } int main() { while(scanf("%d", &n) && n!=-1) { if(n%2) { printf("0/n"); continue; } if(!n) { printf("1/n"); continue; } memset(v, 0, sizeof(v)); printf("%d/n", solve(n)); } return 0; } /* 1. 用记忆性dp的方法; // 2. 0时输出1!(0格时,需板0个,有一种输出方法); Problem: 2663 User: xiaofengsheng Memory: 392K Time: 0MS Language: G++ Result: Accepted */