PAT (Basic Level) 1016 部分A+B (15分)JAVA解法

输入样例 1：

3862767 6 13530293 3

输出样例 1：

399

输入样例 2：

3862767 1 13530293 8

输出样例 2：

0

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.math.BigInteger;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] arr = br.readLine().split(" ");
		char[] A = arr[0].toCharArray();
		char[] B = arr[2].toCharArray();
		char Pa = arr[1].charAt(0);
		char Pb = arr[3].charAt(0);
		int countA=0;
		int countB=0;
		for (int i = 0; i < A.length; i++) {
			if(A[i]==Pa) {
				countA++;
			}
		}
		for (int i = 0; i < B.length; i++) {
			if(B[i]==Pb) {
				countB++;
			}
		}
		if(countA==0 && countB==0) {
			System.out.println(0);
		}else {
			StringBuilder sb1 = new StringBuilder();
			StringBuilder sb2 = new StringBuilder();
			for (int i = 0; i < countA; i++) {
				
				sb1.append(Pa+"");
			}
			for (int i = 0; i < countB; i++) {
				sb2.append(Pb+"");
			}
			BigInteger ba = new BigInteger(sb1.toString());
			BigInteger bb = new BigInteger(sb2.toString());
			System.out.println(ba.add(bb));
		}
		
	}

}