[BaekJoon]2407コンビ

1.  質問リンク

2.  質問する

サマリ

3.  ソースコード

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.math.BigInteger;
import java.util.StringTokenizer;


public class Main {
	public BigInteger getCombination(int n, int m) {
		BigInteger num1 = BigInteger.ONE; // 1
		BigInteger num2 = BigInteger.ONE; // 1
		for(int i = 0; i < m; i++) {
			num1 = num1.multiply(new BigInteger(String.valueOf(n - i))); // BigInteger의 곱셈
			num2 = num2.multiply(new BigInteger(String.valueOf(i + 1))); // BigInteger의 곱셈
		}
		BigInteger result = num1.divide(num2); // BigInteger의 나눗셈
		return result;
	}
	
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        String input = br.readLine();
        br.close();
        StringTokenizer st = new StringTokenizer(input);
        int n = Integer.parseInt(st.nextToken());
        int m = Integer.parseInt(st.nextToken());
        Main main = new Main();
        bw.write(main.getCombination(n, m) + "\n");
        bw.flush();
        bw.close();
    }
}

4.  に近づく