670. Maximum Swap

670. Maximum Swap

Given a non-negative integer, you could swap two digits in most once to get the maximum number. Return the maximum valued number to could get.

Example 1:

input:2736 output:7236 Explanation:swap The number 2 and the number
7.

Example 2:

input:9973
output:9973
explanation:no swap.

Given a nonnegative number, swap the two digits in the number to get the maximum number.

Idea: See code comments

Code:

Package Array;



/**
* @Author oovever
* @Date 2017/11/28 10:10 * * Public
class Solution {public
  int maximumswap (int num) {
      char[] digits = string.valueof (num). ToCharArray ();
      int[] Buckets = new INT[10];
      for (int i=0;i<digits.length;i++) {
//            Find the last position of each number
          Buckets[digits[i]-' 0 ' = i;
      }
      for (int i=0;i<digits.length;i++) {
//            digits traverse buckets from back to current, find number greater than current digits[i] for
          (int j=9;j> digits[i]-' 0 '; j--) {
//                greater than digits[i] number must be greater than Digits[i index
              if (buckets[j) > i) {
                  char temp = Digits[i];
                  Digits[i] = digits[buckets[j]];
                  DIGITS[BUCKETS[J]] = temp;
                  Return integer.valueof (new String (digits));
      }} return num;
  }

}