【bzoj1965】[Ahoi2005]SHUFFLE 洗牌

x*2^m==l (mod n+1)
x=(n/2+1)^m*l mod n+1

#include<algorithm>
#include<iostream>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<queue>
using namespace std;

typedef long long LL;

#define MOD (LL)(n+1LL)

int n,m,l;

LL qpow(LL a,LL b)
{
    LL m=a,s=1LL;
    while (b)
    {
        if (b & 1)
            s=(s*m)%(n+1);
        m=(m*m)%(n+1);
       b>>=1;
    }
    return s;
}

int main()
{
    scanf("%d%d%d",&n,&m,&l);
    printf("%lld",(qpow((LL)n/2+1,m)*l)%(n+1));
    return 0;
}

　　

#include<algorithm>

#include<iostream>

#include<cstdlib>

#include<cstring>

#include<cstdio>

#include<cmath>

#include<queue>

using namespace std;

 

typedef long long LL;

 

#define MOD (LL)(n+1LL)

 

int n,m,l;

 

LL qpow(LL a,LL b)

{

    LL m=a,s=1LL;

    while (b)

    {

        if (b & 1)

            s=(s*m)%(n+1);

        m=(m*m)%(n+1);

       b>>=1;

    }

    return s;

}

 

int main()

{

    scanf("%d%d%d",&n,&m,&l);

    printf("%lld",(qpow((LL)n/2+1,m)*l)%(n+1));

    return 0;

}