1037. Tri Tiling

怎么会WA？
同楼上

怎么会WA？
知道了，不过为什么0时是1，想不通。。你上QQ，我们讨论

像我这种算法能力差的，只能打表过了。

include

include

include

include

using namespace std;
bool v[33][3];
int ans[33];
int n;
/void dfs(int cnt){
//printf(“cnt = %d\n”,cnt);
if(cnt == 3 * n){
ans ++;
return ;
}
for(int i = 0;i < n;i ++){
for(int j = 0;j < 3;j ++){
if(j + 1 < 3 && !v[i][j] && !v[i][j + 1]){
//printf(“i = %d j = %d\n”,i,j);
v[i][j] = v[i][j + 1] = true;
dfs(cnt + 2);
v[i][j] = v[i][j + 1] = false;
}
if(i + 1 < n && !v[i][j] && !v[i + 1][j]){
//printf(“i = %d j = %d\n”,i,j);
v[i][j] = v[i + 1][j] = true;
dfs(cnt + 2);
v[i][j] = v[i + 1][j] = false;
return ; //重复 ！！！
}
//return ;
}
}
}/
int main(){
int n;
ans[0] = 1;
ans[2] = 3;
ans[4] = 11;
ans[6] = 41;
ans[8] = 153;
ans[10] = 571;
ans[12] = 2131;
ans[14] = 7953;
ans[16] = 29681;
ans[18] = 110771;
ans[20] = 413403;
ans[22] = 1542841;
ans[24] = 5757961;
ans[26] = 21489003;
ans[28] = 80198051;
ans[30] = 299303201;
while(scanf(“%d”,&n) && n != -1){
if(n & 1)printf(“0\n”);
else printf(“%d\n”,ans[n]);
}
return 0;
}