标签:des style http java color os
3 4 3 2 3 3 3 3 2 3
8 3HintFor the second example: 0 express face down,1 express face up Initial state 000 The first result:000->111->001->110 The second result:000->111->100->011 The third result:000->111->010->101 So, there are three kinds of results(110,011,101)
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <string>
#include <map>
#include <stack>
#include <vector>
#include <set>
#include <queue>
#define maxn 235
#define MAXN 100005
#define mod 1000000009
#define INF 0x3f3f3f3f
#define pi acos(-1.0)
#define eps 1e-8
typedef long long ll;
using namespace std;
ll n,m,ans,flag,cnt,tot;
ll fac[100005],rev[100005];
ll pow_mod(ll a,ll i,ll n) // 快速幂取模
{
if(i==0)return 1%n;
ll temp=pow_mod(a,i>>1,n);
temp=temp*temp%n;
if(i&1)temp=temp*a%n;
return temp;
}
void init() // 初始化
{
fac[0]=rev[0]=1;
for(ll i=1;i<=100000;i++)
fac[i]=fac[i-1]*i%mod,rev[i]=pow_mod(fac[i],mod-2,mod);
}
ll C(ll n,ll m) // 求组合数取mod的值
{
return (fac[n]*rev[m]%mod)*rev[n-m]%mod;
}
int main()
{
ll i,j,t,x,le,ri;
init();
while(~scanf("%I64d%I64d",&n,&m))
{
le=ri=0;
for(i=1;i<=n;i++)
{
scanf("%I64d",&x);
ll u,v;
if(x<=le) u=le-x;
else if(x>le&&x<ri)
{
if((x+le)%2==0) u=0;
else u=1;
}
else u=x-ri;
if(x<=m-ri) v=ri+x;
else if(x>m-ri&&x<=m-le)
{
if((x+le+m)%2==0) v=m;
else v=m-1;
}
else v=le+(m-le)-(x-(m-le));
le=u,ri=v;
}
// printf("le:%I64d ri:%I64d\n",le,ri);
ans=0;
for(i=le;i<=ri;i+=2)
{
ans+=C(m,i);
ans%=mod;
}
printf("%I64d\n",ans);
}
return 0;
}hdu 4869 Turn the pokers (思维),布布扣,bubuko.com
标签:des style http java color os
原文地址:http://blog.csdn.net/tobewhatyouwanttobe/article/details/38052723