mirror of
https://github.com/Kiritow/OJ-Problems-Source.git
synced 2024-03-22 13:11:29 +08:00
70 lines
1.9 KiB
C++
70 lines
1.9 KiB
C++
|
#include <cstdio>
|
||
|
|
#include <cstdlib>
|
||
|
|
#include <cmath>
|
||
|
|
#include <cstring>
|
||
|
|
#include <string>
|
||
|
|
#include <queue>
|
||
|
|
#include <map>
|
||
|
|
#include <iostream>
|
||
|
|
#include <algorithm>
|
||
|
|
using namespace std;
|
||
|
|
#define RD(x) scanf("%d",&x)
|
||
|
|
#define RD2(x,y) scanf("%d%d",&x,&y)
|
||
|
|
#define RD3(x,y,z) scanf("%d%d%d",&x,&y,&z)
|
||
|
|
#define clr0(x) memset(x,0,sizeof(x))
|
||
|
|
typedef long long LL;
|
||
|
|
const int maxn = 1<<20;
|
||
|
|
int n,k;
|
||
|
|
LL f[20][20],dp[maxn],tmp[maxn];
|
||
|
|
int cal(int x)
|
||
|
|
{
|
||
|
|
int ans = 0;
|
||
|
|
for(int i = 0;i < 20;++i)
|
||
|
|
if((1<<i)&x)
|
||
|
|
ans++;
|
||
|
|
return ans;
|
||
|
|
}
|
||
|
|
void init () {
|
||
|
|
dp[1] = f[1][1] = 1;
|
||
|
|
for(int i = 1;i < 18;++i){
|
||
|
|
for(int j = 0;j < (1<<i);++j)
|
||
|
|
tmp[j] = dp[j];
|
||
|
|
for(int j = 0;j < (1<<(i+1));++j)
|
||
|
|
dp[j] = 0;
|
||
|
|
for(int j = 0;j < (1<<i);++j)if(tmp[j]){
|
||
|
|
for(int k = 0;k <= i;++k){
|
||
|
|
int tot = 0,c[20],st = 0;
|
||
|
|
for(int l = 0;l < i;++l){
|
||
|
|
if((1<<l) & j){
|
||
|
|
c[tot] = l;
|
||
|
|
if(c[tot] >= k)
|
||
|
|
c[tot]++;
|
||
|
|
tot++;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
c[tot++] = k;
|
||
|
|
for(int l = 0;l < tot;++l){
|
||
|
|
if(c[l] > k){
|
||
|
|
c[l] = k;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
for(int l = 0;l < tot;++l){
|
||
|
|
st |= (1<<c[l]);
|
||
|
|
}
|
||
|
|
dp[st] += tmp[j];
|
||
|
|
}
|
||
|
|
}
|
||
|
|
for(int j = 0;j < (1<<(i+1));++j)
|
||
|
|
f[i+1][cal(j)] += dp[j];
|
||
|
|
}
|
||
|
|
}
|
||
|
|
int main() {
|
||
|
|
init();
|
||
|
|
int _;RD(_);while(_--){
|
||
|
|
RD2(n,k);
|
||
|
|
printf("%I64d\n",f[n][k]);
|
||
|
|
}
|
||
|
|
return 0;
|
||
|
|
}
|