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contents/algorithms/binary.md

@@ -3,7 +3,38 @@ id: binary
 title: Binary
 ---
 
-- How do you verify if an interger is a power of 2?
+## Study links
+
+- [Bits, Bytes, Building With Binary](https://medium.com/basecs/bits-bytes-building-with-binary-13cb4289aafa)
+
+## Notes
+
+Questions involving binary representations and bitwise operations are asked sometimes and you must be absolutely familiar with how to convert a number from decimal form into binary form (and vice versa) in your chosen programming language.
+
+Some helpful utility snippets:
+
+- Test k<sup>th</sup> bit is set: `num & (1 << k) != 0`.
+- Set k<sup>th</sup> bit: `num |= (1 << k)`.
+- Turn off k<sup>th</sup> bit: `num &= ~(1 << k)`.
+- Toggle the k<sup>th</sup> bit: `num ^= (1 << k)`.
+- To check if a number is a power of 2, `num & num - 1 == 0`.
+
+## Corner cases
+
+- Be aware and check for overflow/underflow
+- Negative numbers
+
+## Recommended Leetcode questions
+
+- [Sum of Two Integers](https://leetcode.com/problems/sum-of-two-integers/)
+- [Number of 1 Bits](https://leetcode.com/problems/number-of-1-bits/)
+- [Counting Bits](https://leetcode.com/problems/counting-bits/)
+- [Missing Number](https://leetcode.com/problems/missing-number/)
+- [Reverse Bits](https://leetcode.com/problems/reverse-bits/)
+
+## More questions
+
+- How do you verify if an integer is a power of 2?
 - Write a program to print the binary representation of an integer.
 - Write a program to print out the number of 1 bits in a given integer.
 - Write a program to determine the largest possible integer using the same number of 1 bits in a given number.