Add One to List - Amazon Top Interview Questions


Problem Statement :


You are given a list of integers nums, representing a decimal number and nums[i] is between [0, 9].

For example, [1, 3, 9] represents the number 139.

Return the same list in the same representation except modified so that 1 is added to the number.

Constraints

1 ≤ n ≤ 100,000 where n is the length of nums.


Example 1

Input
nums = [1, 9, 1]

Output
[1, 9, 2]



Example 2

Input
nums = [9]


Output
[1, 0]



Solution :



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                        Solution in C++ :

vector<int> solve(vector<int>& nums) {
    if (nums.empty()) return nums;

    int i = nums.size() - 1;
    while (nums[i] == 9 && i != 0) {
        nums[i] = 0;
        i--;
    }

    if (nums.size() == 100000 && nums[i] == 9) return nums;

    if (nums[i] == 9) {
        nums[i] = 1;
        nums.push_back(0);
    } else
        nums[i] += 1;

    return nums;
}
                    


                        Solution in Java :

import java.util.*;

class Solution {
    public int[] solve(int[] nums) {
        if (nums[nums.length - 1] < 9) {
            nums[nums.length - 1] += 1;
            return nums;
        }
        int[] rtn = new int[nums.length + 1];
        int carry = 1;
        for (int i = nums.length - 1; i >= 0; i--) {
            if (nums[i] < 9) {
                nums[i] += carry;
                return nums;
            } else
                nums[i] = 0;
        }
        rtn[0] = 1;
        return rtn;
    }
}
                    


                        Solution in Python : 
                            
class Solution:
    def solve(self, nums):
        i = len(nums) - 1
        while i >= 0:
            if nums[i] + 1 <= 9:
                nums[i] = nums[i] + 1
                break
            else:
                nums[i] = 0
            i -= 1
        if i < 0:
            nums.insert(0, 1)
        return nums
                    


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