Topics needed to cover in order of their importance.

1. stl in c++ / equivalent .
2. Basic maths , basic logic
3. Searching — Sorting , greedy , two pointers ,sliding window
4. Implementation , stl based
5. Binary search ( very important and a saviour)
6. Number theory ( sieve , gcd , factorisation , prime numbers etc )
7. Basic bit manipulation and basic combinatorics. (very basic)

do 50 problems each 800->900->1000->1100->1200->1300->1400

most important thing that u need to practice on is ---> Strong implementation and speed.