PlusOne.cpp

// LEETCODE 66. {EASY} {ARRAY}

// You are given a large integer represented as an integer array digits, where each digits[i] is the ith digit of the integer. The digits are ordered from most significant to least significant in left-to-right order. The large integer does not contain any leading 0's.

// Increment the large integer by one and return the resulting array of digits.


// Example 1:

// Input: digits = [1,2,3]
// Output: [1,2,4]
// Explanation: The array represents the integer 123.
// Incrementing by one gives 123 + 1 = 124.
// Thus, the result should be [1,2,4].
// Example 2:

// Input: digits = [4,3,2,1]
// Output: [4,3,2,2]
// Explanation: The array represents the integer 4321.
// Incrementing by one gives 4321 + 1 = 4322.
// Thus, the result should be [4,3,2,2].
// Example 3:

// Input: digits = [9]
// Output: [1,0]
// Explanation: The array represents the integer 9.
// Incrementing by one gives 9 + 1 = 10.
// Thus, the result should be [1,0].
 

// Constraints:

// 1 <= digits.length <= 100
// 0 <= digits[i] <= 9
// digits does not contain any leading 0's.

### Solution

```
class Solution {
public:
    vector<int> plusOne(vector<int>& digits) {
        int n = digits.size();
        int i  = n-1;
        while(i>=0)
        {
            digits[i]++;
            if(digits[i]>=10)
            {
                digits[i] = digits[i]%10;
                i--;
            }
            else
                break;
        }
        if (i == -1)
            digits.insert(digits.begin(), 1);
        return digits;
    }
};
```