# Find and Replace Pattern (Leetcode 890)

Difficulty: Medium Link: Day 21: May Leetcode Challenge Problem Description Given a list of strings words and a string pattern, return a list of words[i] that match pattern. You may return the…

# Interval List Intersections (Leetcode 986)

Difficulty: Medium Link: Leetcode 986 Problem Statement You are given two lists of closed intervals, firstList and secondList, where firstList[i] = [starti, endi] and secondList[j] = [startj, endj]. Each list of…

# Non-decreasing Array (Leetcode 665)

Difficulty: Medium Link: Day 4 : May Leetcode Challenge Problem Description Given an array nums with n integers, your task is to check if it could become non-decreasing by…

# Count Binary Substrings

Difficulty : Easy Link: Leetcode April Challenge 2021: Day 23 Problem Description Give a string s, count the number of non-empty (contiguous) substrings that have the…

# Brick Wall (Leetcode 554)

Difficulty: Medium Tag: April Leetcode Challenge: Day 22 Problem Statement There is a brick wall in front of you. The wall is rectangular and has…

# Remove Nth Node From End of List (Leetcode 19)

Difficulty: Medium . This problem is taken from Day 18 problem of April Leetcoding 2021: Problem Statement Given the head of a linked list, remove the nth node from…

# Remove All Adjacent Duplicates In String (Leetcode 1047)

Difficulty: Easy Link: Leetcode Problem Statement Given a string S of lowercase letters, a duplicate removal consists of choosing two adjacent and equal letters, and removing them. We repeatedly make…

# Remove All Adjacent Duplicates in String II (Leetcode 1209)

Difficulty : Medium Link: April Leetcoding Challenge : Day 16 Problem Statement Given a string s, a k duplicate removal consists of choosing k adjacent and equal letters from s and removing them causing…

# Fibonacci Number (Leetcode 509)

Difficulty: Easy Link: April Leetcoding Challenge: Day 15 The Fibonacci numbers, commonly denoted F(n) form a sequence, called the Fibonacci sequence, such that each number is the sum of…

# Diameter of Binary Tree (Leetcode 543)

Difficulty : Easy Link: Leetcode 543 Problem Description Given the root of a binary tree, return the length of the diameter of the tree. The diameter of a binary tree is the length of…