[코테 풀이] Maximum 69 Number

Q_1323) Maximum 69 Number

출처 : https://leetcode.com/problems/maximum-69-number/

You are given a positive integer num consisting only of digits 6 and 9.

Return the maximum number you can get by changing at most one digit (6 becomes 9, and 9 becomes 6).

class Solution {
    public int maximum69Number (int num) {
        String number = Integer.toString(num);
        String answer = "";
        for (int i = 0; i < number.length(); i++) {
            if (number.charAt(i) == '6') {
                answer += number.substring(0,i)+'9'+number.substring(i+1);
                break;
            }
        }
        if(answer.length()>=1) return Integer.parseInt(answer);
        else return num;
    }
}