zoj 2994 Tiling a Grid With D...

#include<stdio.h>int main(){int a[20], i, j, sum;a[1] = 1;a[2] = 5;for (i = 3; i <= 19; i++){sum = i % 2 ? 2 : 3;for (j = 1; j < i; j++)if (j == 1)sum += a[i - 1];else if (j == 2)sum += 4 * a[i - 2];elsesum += (j % 2 ? 2 : 3) * a[i - j];a[i] = sum;}int n;scanf("%d", &n);for (i = 1; i <= n; i++){scanf("%d", &j);printf("%d %dn", i, a[j]);}return 0;}