problems in Online judges like codeforces,Spoj,hackerearth etc problems that i tried in online judges like codeforces,SPOJ
- 1 -Two Sum - Accepted
- 7 -Reverse Integer -Accepted
- 9 -Palindrome Number - in two ways -> first one is making string reverse,other one is doing the reverse and checking(Accepted)
- 13 -Roman To Integer - Accepted
- 20 - Valid Parentheses - Accepted
- 101 - Symmetric Tree
- 102 - Binary Tree Level Order Traversal
- 342 -Power of four(checking reminder method-log(n),Logarithomic solution(coomplexity-Math.Log function of Java))
- 520 - Detect Capital(bruitForce(2m,40% daster),counting uppercase(1ms,99.55% faster))
- 705 - Hashmap impementation
- 121 - BestTime to buy and sell stock
- 50 - Pow(x, n)
- 94 - Binary Tree Inorder Traversal
- 242 - Valid Anagram
- 595 -Big Countries - where and union operator was used..second apporach - OR operator
- 627 - Swap salaries - swaping values in a column using SET,CASE and WHEN
- 1179 - Reformat Department Table
- 175 -Joining two tables - used Left joining to do it
- 176 - Second Highest Salary - used subquery to do it
- 177 - Nth Highest salary - using Limit , Order and OFFSET
- 196 - Delete duplication - https://github.com/PlabonKumarsaha/Problem_Solutions_OJ/blob/master/LeedCodeSQL/196Delete%20Duplicate%20Emails.txt
- 178 - Rank Score - using ,dense_rank()
- 620 - Not Boring Movies- desc
- 182 - Duplicate Emails
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- Customers Who Never Order - using NOT IN
- 12hrTo24hrConversion
- Counting vallys
- desigingPDF
- PassordPattern