1020C - Elections
Using unordered_set : 317095466
Using unordered_map : 317200168

How to make unordered_set work?????

I've been trying to improve on Codeforces, and I'm currently aiming to solve 1500-rated problems. However, whenever I read the problem statements of some 1600-rated questions, I feel completely lost.

What concepts or implementation skills should I focus on to bridge this gap and make consistent progress? I'd love to hear your thoughts, advice, or personal experiences!

I’m just starting to learn dynamic programming (DP) and I want to make sure I avoid any common pitfalls. If you were in my position, is there anything you regret doing while learning DP, or any mistakes you think I should avoid?

Everyone's telling me I should learn binary search, but I feel lost when I hit the problem sets. I just don’t get how to apply binary search to them. Can someone give me some ideas or directions to improve?? I understand when I should implement upper_bound or lower_bound, but I don't fully understand the deeper implementation details

I've been doing competitive programming for about 2-3 months and have gone through these topics so far:

• Basics (Conditional statements, loops, switch)
• Bitwise operators
• Arrays, Strings
• Greedy algorithms
• Linear search, Two pointers
• Binary search
• Prefix sum
• Sorting
• Number Theory (sieve, modulo, exponentiation)
• Pointers
• STL
• Recursion
• Basic Probability and Combinatorics

Lately, I've been practicing questions in the 1000-1400 range.

Next, I'm thinking of diving into:

• Stack

• Queue

• Tree

• Heap

• Hashmap

• Trie

• Backtracking

• Graph (BFS, DFS, Shortest Path)

• Dynamic Programming

Does this sequence seem okay? Any tips on how to approach these topics?

Is it acceptable to skip learning OOPs and Linked Lists for now while focusing on C++ and DSA for competitive programming?