zoj 2745 01

zoj 2745 01

#include <iostream>#include <cstdio>#include <cstring>#define lng long longusing namespace std;int n, k;lng dp[100][10][10];int main(){ while(~scanf("%d %d", &n, &k)) { for(int i = 0; i <= n; ++i) for(int j = 0; j <= k; ++j) for(int q = 0; q <= k; ++q) dp[i][j][q] = 0; dp[0][0][0] = 1; for(int i = 1; i <= n; ++i) { for(int j = 0; j <= k; ++j) { for(int q = 0; q <= k; ++q) { if(j + q <= k) { dp[i][max(0, j - 1)][q + 1] += dp[i - 1][j][q]; dp[i][j + 1][max(0, q - 1)] += dp[i - 1][j][q]; } } } } lng res = 0; for(int i = 0; i <= k; ++i) for(int j = 0; j <= k; ++j) if(i + j <= k) res += dp[n][i][j]; printf("%lldn", res); } return 0;}