- Largest Sum contiguous subarray in sum
- Take care ofindex_out_of_bounds error.
- Kadane
- Maximum sum of k elements
- Unique subsequent alphabets in a string length,
- map.containsKey(x)
- map.put will put the key if it was not present and update it if it is present.
- time_complexity will be O(n),space_complexity will be O(n)