2734. Lexicographically Smallest String After Substring Operation
IntuitionApproachComplexity
Time complexity:

Space complexity:
Code
# Intuition
<!-- Describe your first thoughts on how to solve this problem. -->

# Approach
<!-- Describe your approach to solving the problem. -->

# Complexity
- Time complexity:
<!-- Add your time complexity here, e.g. $$O(n)$$ -->

- Space complexity:
<!-- Add your space complexity here, e.g. $$O(n)$$ -->

# Code
```cpp []
class Solution {
public:
    string smallestString(string s) {
        int n = s.size();
        int i = 0;

        while (i < n && s[i] == 'a') i++;
        if (i == n) {
            s[n - 1] = 'z';
            return s;
        }

        while (i < n && s[i] != 'a') {
            s[i] = s[i] - 1;
            i++;
        }
        return s;
    }
};

```
['C++']