模重复平方算法

 

计算a^x(mod m)的值。

#include<iostream>
using namespace std;
int Square_and_Multiply(int a, int x, int m)
{
    int i = 1,result=1;
    for (i = 1; i <= x; i++)
    {
        result =( a*result )% m;
    }
    return result;
}
int main()
{
    int a, b, m,result;
    cout << "求a的b次方mod m的值，请依次输入a,b,m的值  ";
    cin >> a >> b >> m;
    result = Square_and_Multiply(a, b, m);
    cout<< endl<<result;
    system("pause");
    return 0;

}