- Get array of split input of integers
[int(x) for x in input().split()]- For sorting a 2D array based on 0th column
arr.sort(key=lambda x: x[0])Note: this sorts the array directly and overwrites it. Does not return a value
- For taking input of space-separated data
list(map(int,input().split())) # Replace int with str for strings- For outputting to one decimal place:
print( round(ans, 1) )- Find all permutations of characters in a string
import itertools
s = 'ABC'
nums = list(s)
perms = list(itertools.permutations(nums)) # Recursion Tree- Remove duplicates from an array
mylist = list(dict.fromkeys(mylist))import re- Find all occurrences of a substring in a string
re.findall(substring, string) # Substring can also be a pattern- [vectors](https://www.cplusplus.com/reference/vector/vector/) are dynamic arrays
- vectors are very efficient accessing its elements (just like arrays) and relatively efficient adding or removing elements from its end. For operations that involve inserting or removing elements at positions other than the end, they perform worse than the others, and have less consistent iterators and references than lists and forward_lists
- C++ WILL TURN OUTPUT TO SCI NOTATION IF TOO LARGE, USE
```c++
cout << fixed << ans;
```