1629번 곱셈

 

문제 

 

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

 

 

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문제 풀이

public class Main {
	public static StringBuilder sb = new StringBuilder();
	public static int [] count = new int[3];
	public static int arr [][];
	public static void main(String[] args) throws IOException {
		BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer st = new StringTokenizer(bf.readLine()); 
		long a = Long.parseLong(st.nextToken());
		long b = Long.parseLong(st.nextToken());
		long c = Long.parseLong(st.nextToken());
		System.out.println(pow(a,b,c));
	}  
	public static long pow(long a, long b, long c) {
		if (b == 1) {
			return a % c;
		}
		long res = pow(a, b/2, c);
		 if (b % 2 == 0) {
			return res * res % c;
			
		}
		else {
			return (res * res % c) * a % c;
		}
	}
}