poj 2411 Mondriaan's Dream

#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
#define LL long long
const int bit= 12;
const int maxn = 1<<bit;

LL dp[bit][bit][maxn];

inline bool get(int x,int pos){
return (x>>pos)&1;
}
inline int sub(int x,int pos){
return x & (~(1<<pos));
}

int main(){
int n,m;
while(~scanf("%d %d",&n,&m) && (n||m)){
memset(dp,0,sizeof(dp));
int bnd = 1<<m;
dp[0][m-1][bnd-1] = 1;
for(int i=1;i<=n;i++){
for(int j=0;j<m;j++){
LL *pdp = !j ? dp[i-1][m-1]:dp[i][j-1];
for(int mask=0;mask<bnd;mask++){
if(get(mask,j)){
dp[i][j][mask] = pdp[sub(mask,j)];
if(j && get(mask,j-1)){
dp[i][j][mask] += pdp[sub(mask,j-1)];
}
}
else{
dp[i][j][mask] = pdp[mask | (1<<j)];
}
}
}
}
printf("%lld\n",dp
[m-1][bnd-1]);
}
return 0;
}