TopCoder SRM 176 Deranged
1515 단어 topcoder
#include<iostream>
#include<cstring>
#include<cstdio>
#include<string>
#include<set>
#include<map>
#include<cmath>
#include<algorithm>
#include<vector>
#include<cmath>
#include<queue>
#include<stack>
//#define ull unsigned long long
#define ll long long
using namespace std;
const int INF=0x3f3f3f3f;
const int MOD=1000003;
const int N=15;
ll dp0[1<<N],dp1[1<<N];
ll factorial[N];
class Deranged
{
public:
long long numDerangements(vector <int> nums)
{
int n=nums.size();
memset(dp0,0,sizeof(dp0));
dp0[(1<<n)-1]=1;
for(int w=0;w<n;++w)
{
memset(dp1,0,sizeof(dp1));
for(int i=0;i<(1<<n);++i)
{
for(int j=0;j<n;++j)
if((i&(1<<j))&&nums[j]!=nums[w])
{
dp1[i^(1<<j)]+=dp0[i];
}
}
memcpy(dp0,dp1,sizeof(dp0));
}
ll sum=dp0[0];
factorial[0]=1;
for(int i=1;i<=n;++i)
factorial[i]=factorial[i-1]*i;
for(int i=0;i<n;++i)
{
int x=0;
for(int j=0;j<n;++j)
{
if(nums[j]==i)
++x;
}
sum/=factorial[x];
}
return sum;
}
};