package MyArrays;

import org.junit.Test;

/**

* @description: 描述 Easy

* @author: dekai.kong

* @date: 2018-12-13 16:22

* @from https://leetcode.com/problems/plus-one/

* Given a non-empty array of digits representing a non-negative integer, plus one to the integer.

*

* The digits are stored such that the most significant digit is at the head of the list, and each element in the array contain a single digit.

*

* You may assume the integer does not contain any leading zero, except the number 0 itself.

*

* Example 1:

*

* Input: [1,2,3]

* Output: [1,2,4]

* Explanation: The array represents the integer 123.

* Example 2:

*

* Input: [4,3,2,1]

* Output: [4,3,2,2]

* Explanation: The array represents the integer 4321.

*/

public class PlusOne {

public PlusOne() {

}

/**

* Runtime: 0 ms, faster than 100.00% of Java online submissions for Plus One.

* @param digits

* @return

*/

public int[] plusOne(int[] digits) {

int up = 0;

for (int i = digits.length-1; i >= 0; i--) {

if(digits[i] == 9){

digits[i] = 0;

up = 1;

}else{

digits[i] = digits[i]+1;

up = 0;

break;

}

}

if(up == 1){

int[] d = new int[digits.length+1];

System.arraycopy(digits,0,d,1,digits.length);

d[0] = 1;

return d;

}

return digits;

}

@Test

public void test() {

System.out.println(plusOne(new int[]{4,3,2,1}));

System.out.println(plusOne(new int[]{9,9,9,9}));

System.out.println(plusOne(new int[]{2,4,9,3,9}));

}

}