70 lines
1.9 KiB
C++
70 lines
1.9 KiB
C++
#include <cstdio>
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#include <cstdlib>
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#include <cmath>
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#include <cstring>
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#include <string>
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#include <queue>
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#include <map>
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#include <iostream>
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#include <algorithm>
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using namespace std;
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#define RD(x) scanf("%d",&x)
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#define RD2(x,y) scanf("%d%d",&x,&y)
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#define RD3(x,y,z) scanf("%d%d%d",&x,&y,&z)
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#define clr0(x) memset(x,0,sizeof(x))
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typedef long long LL;
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const int maxn = 1<<20;
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int n,k;
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LL f[20][20],dp[maxn],tmp[maxn];
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int cal(int x)
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{
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int ans = 0;
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for(int i = 0;i < 20;++i)
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if((1<<i)&x)
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ans++;
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return ans;
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}
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void init () {
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dp[1] = f[1][1] = 1;
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for(int i = 1;i < 18;++i){
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for(int j = 0;j < (1<<i);++j)
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tmp[j] = dp[j];
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for(int j = 0;j < (1<<(i+1));++j)
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dp[j] = 0;
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for(int j = 0;j < (1<<i);++j)if(tmp[j]){
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for(int k = 0;k <= i;++k){
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int tot = 0,c[20],st = 0;
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for(int l = 0;l < i;++l){
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if((1<<l) & j){
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c[tot] = l;
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if(c[tot] >= k)
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c[tot]++;
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tot++;
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}
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}
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c[tot++] = k;
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for(int l = 0;l < tot;++l){
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if(c[l] > k){
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c[l] = k;
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break;
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}
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}
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for(int l = 0;l < tot;++l){
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st |= (1<<c[l]);
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}
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dp[st] += tmp[j];
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}
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}
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for(int j = 0;j < (1<<(i+1));++j)
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f[i+1][cal(j)] += dp[j];
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}
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}
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int main() {
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init();
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int _;RD(_);while(_--){
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RD2(n,k);
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printf("%I64d\n",f[n][k]);
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}
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return 0;
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}
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