import java.io.IOException;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) throws IOException {
        String num1, num2;
        // user String to save **** int
        Scanner in = new Scanner(System.in);
        num1 = in.nextLine();
        num2 = in.nextLine();
        int A = 0, B = 0;
        for (int i = 0; i < 4; i++) {
            for (int j = 0; j < 4; j++) {
                if (num1.charAt(i) == num2.charAt(j))
                    B++;
            }
        }

        for (int i = 0; i < 4; i++) {
            if (num1.charAt(i) == num2.charAt(i))
                A++;
        }
        System.out.println(A + "A" + (B - A) + "B");

    }
}

------解决方案--------------------
Java code

public static void main(String[] args) {
        int a = 5673;
        int b = 5013;
        HashMap list = new HashMap();
        while (a > 0) {
            list.put(list.size(), a % 10);
            a /= 10;
        }
        int k1 = 0, k2 = 0;
        int i = 0;
        while (b > 0) {
            int t = b % 10;
            if (list.containsValue(t)) {
                if (list.get(i) == Integer.valueOf(t))
                    k1++;
                else
                    k2++;
            }
            i++;
            b /= 10;
        }
        System.out.println(k1 + "A" + k2 + "B");
    }

------解决方案--------------------
Java code

      int A = 0;
      int B = 0;

      String s1 = "5673";
      String s2 = "0153";

      if(s1.length() == s2.length()) {
         for(int i = 0; i < s1.length(); i++) {
            char c1 = s1.charAt(i);

            for(int j = 0; j < s2.length(); j++) {
               char c2 = s2.charAt(j);

               if(c1 == c2) {
                  if(i == j) {
                     A++;
                  }
                  else {
                     B++;
                  }
               }
            }
         }
      }

      System.err.println(A + "A" + B + "B");

------解决方案--------------------
Java code

    public static void main(String[] args){
        int a = 0, b = 0;
        String s1 = "5673";
        String s2 = "5013";
        for (int j = 0, i = 0; i<s1.length();)
        {
            if (s1.charAt(i)==s2.charAt(j)){
                if (i==j){
                    a++;
                }
                else{
                    b++;
                }
            }
            j++;
            if (j==s1.length()){
                i++;
                j = 0;
            }
        }
        System.out.println(a+"A"+b+"B");
    }

------解决方案--------------------
Java code

char [] num1 = new Integer(5673).toString().toCharArray();
        char [] num2 = new Integer(5013).toString().toCharArray();
        int counterA = 0, counterB = 0;
        for (int i = 0; i < 4; i++) {
            for (int j = 0; j < 4; j++) {
                if (j!=i&&num1[i] == num2[j])
                    counterB++;
            }
            if (num1[i] == num2[i] )counterA++;                
        }
        System.out.println(counterA + "A" + counterB + "B");