/*  scfcpown.cpp  by K.Tsuru  */
// function ID = 9103
/********************************
SComplex class
It returns z^n.
*********************************/
#ifndef SN_H
#include "sn.h"
#endif
SComplex Cpow(const SComplex& z, int n){
    SComplex y(1.0), r;
    if( z.IsZero(9103) ){// 0^n
        SNManager::SetError(SNManager::DOMAIN_ERR, "Cpow z=0", 9103);
    }
    if(n == 0) return y;    // 1.0

    if(n < 0){
        r = y/z;    // y = 1, "1/z" is an error.
        n = -n;
    }else r = z;

    while(1){
        if(n % 2) y *= r;
        n /= 2;
        if( !n ) break;
        r *= r;
    }
    return y;
}