CINTA作业7-编程题【模指数】

CINTA

/*
* Input: three integers:x,y and m
* Output: (x^y)%m
* Method: iterative method
*/
int ModulusIndex(int x,int y,int m){
    int res=1;
    while(y){
        if(y&1){
            res=res*x%m;
        }
        x=x*x%m;
        y=y>>1;
    }
    return res;
}