模的指数运算的c语言实现

#include <iostream>
#include <cstdio>using namespace std;//模的指数运算
int modexp(int x,int y,int N);//x为底数，y为指数，N为取模的数字int main()
{int x,y,N;int ans;cin>>x>>y>>N;ans=modexp(x,y,N);cout<<ans<<endl;return 0;
}int modexp(int x,int y,int N)
{if(y==0) return 1;int z=modexp(x,y/2,N);if(y%2==0) return z*z % N;else return x*z*z % N;
}