hoj 2662（状态压缩dp）

#include <iostream>#include <cstdio>#include <cstring>#define Max 1<<9using namespace std;typedef long long LL;LL n, m, k;LL p;LL status[Max], num[Max];LL dp[81][21][Max];bool Check(LL x) {if(x & (x << 1))return false;return true;}LL GetNum(LL x) {LL ans = 0;while(x) {if(x & 1)ans++;x >>= 1;}return ans;}void Init() {LL i;p = 0;memset(dp, 0, sizeof(dp));for(i = 0; i < (1 << m); i++)if(Check(i)) {status[p] = i;num[p++] = GetNum(i);}}int main() {LL r, i, l, j;while(~scanf("%lld%lld%lld", &n, &m, &k)) {if(!(n && m)) {printf("0\n");continue;}if(n < m) {int temp;temp = n; n = m;m = temp;}Init();for(i = 0; i < p; i++)dp[1][num[i]][i] = 1;for(r = 2; r <= n; r++)for(i = 0; i < p; i++)for(l = 0; l < p; l++)if(!(status[i] & status[l]))for(j = 0; j <= k; j++)if(j - num[i] >= 0)dp[r][j][i] += dp[r - 1][j - num[i]][l];LL ans = 0;for(i = 0; i < p; i++)ans += dp[n][k][i];printf("%lld\n", ans);}return 0;}