mirror of
https://github.com/Kiritow/OJ-Problems-Source.git
synced 2024-03-22 13:11:29 +08:00
55 lines
1.4 KiB
C++
55 lines
1.4 KiB
C++
#include <iostream>
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#include <cstdio>
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#include <algorithm>
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#include <string.h>
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using namespace std;
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typedef long long ll;
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const int mod = 1000000007;
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int dp[15][1<<15];
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int sum[1<<15];
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int sub[1<<15];
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int L[15],R[15],n;
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int cal(int S){
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int num=0;
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for(int i=0; i<n; ++i)
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if(S&(1<<i)) num++;
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return num;
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}
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int main()
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{
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int cas;
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scanf("%d",&cas);
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for(int cc= 1; cc<=cas; ++cc){
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scanf("%d",&n);
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for(int i=0; i<n; ++i)
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scanf("%d%d",&L[i],&R[i]);
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for(int i=0; i<n; ++i){
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dp[i][0]=1;
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}
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sum[0]=1; sub[0]=1;
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for(int S=1; S<(1<<n); ++S){
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sum[S]=0; sub[S]=0;
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int ge = cal(S);
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for(int i =0; i<n; ++i){
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dp[i][S]=0;
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if( ( S&(1<<i) )!=0 && L[i]<=ge&&R[i]>=ge ){
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dp[i][S]= sub[S^(1<<i)];
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sum[S]= (dp[i][S]+sum[S])%mod;
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}
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}
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int j=0;
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for( j=0; j<n; ++j ) if(S&(1<<j)) break;
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for(int H=S; H>0; H=S&(H-1)){
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if((H&(1<<j))==0) continue;
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ll a = sum[H];
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ll b = sub[S^H];
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sub[S]= ( sub[S] + a*b%mod )%mod;
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}
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}
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int ans=0;
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for(int i=0; i<n; ++i) ans=(ans+ dp[i][(1<<n)-1])%mod;
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printf("%d\n",ans);
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}
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return 0;
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}
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