백준 1629 곱셈 C++

[문제 링크]

https://www.acmicpc.net/problem/1629

[입출력 예]

입력	출력
10 11 12	4

[소스코드]

//시작시간 10:48
#include <bits/stdc++.h>
#define ll long long
using namespace std;

ll func (int a, int b, int c){
  if (b==1){
    return a % c;
  }


 if (b%2 ==0){
    return func(a, b/2, c)*func(a,b/2,c)%c;
  }
  else {
    return func(a,b/2,c)*func(a,b/2,c)%c*a%c;
  }
}


int main(){
  ios::sync_with_stdio(0);
  cin.tie(0);

  int a,b,c;
  cin>>a>>b>>c;
  cout<<func(a,b,c);



  return 0;
}