python3

javascript

java

Remove K Digits

Given string num representing a non-negative integer ``num``, and an integer ``k``, return the *smallest possible integer after removing* ``k`` *digits from* ``num.``

### Input Format

First Parameter:  String ``num``

Second Parameter: Integer ``k``
### Output Format
Return the String
### Example 1
```
Input: num = "1432219", k = 3
Output: "1219"
Explanation: Remove the three digits 4, 3, and 2 to form the new number 1219 which is the smallest.
```
### Example 2
```
Input: num = "10200", k = 1
Output: "200"
Explanation: Remove the leading 1 and the number is 200. Note that the output must not contain leading zeroes.
```
### Example 3
```
Input: num = "10", k = 2
Output: "0"
Explanation: Remove all the digits from the number and it is left with nothing which is 0.
```
#### Constraints
- 1 <= k <= nums.length <= 10^5^
- ``num`` consists of only digits.
- `` num`` does not have any leading zeros except for the zero itself.
- Expected Time Complexity - O(n) 
- Expected Space Complexity - O(n)

string solve(string num, int k){
//CODE HERE 
}

static String solve(String num, int k){
//CODE HERE 
}