This Repository contains solutions to 450 Data Structures and Algorithms!

1. Reverse the array | Time Complexity => O(n)
2. Find the maximum and minimum element in an array | Time Complexity => O(n)
3. Find the "Kth" max and min element of an array | Time Complexity => O(n)
4. Given an array which consists of only 0, 1 and 2. Sort the array without using any sorting algo | Time Complexity => O(n)
5. Move all the negative elements to one side of the array | Time Complexity => O(n) | Auxiliary Space => O(1)
6. Find the Union and Intersection of the two sorted arrays. | Time Complexity => O(m + n)
7. Write a program to cyclically rotate an array by one. | Time Complexity => O(n) | Auxiliary Space => O(1)
8. find Largest sum contiguous Subarray [V. IMP] | Kadane's Algo [V.V.V.V.V IMP] | Time Complexity => O(n)
9. Minimise the maximum difference between heights [V.IMP] | Time Complexity => O(nlogn)
10. Minimum no. of Jumps to reach end of an array | Time Complexity => O(n) | Auxiliary Space => O(1)
11. find duplicate in an array of N+1 Integers | Time Complexity => O(n) | Auxiliary Space => O(1)
12. Merge 2 sorted arrays without using Extra space. | Time Complexity => O((n+m)*log(n+m)) | Auxiliary Space => O(1)
13. Merge Intervals | Time Complexity => O(nlogn)
14. Next Interval | Time Complexity => O(n)
15. Count Inversions | Time Complexity => O(nlogn)
16. Best Time to Buy and Sell | Time Complexity => O(n)
17. Two Sum Problem | Find all pairs on integer array whose sum is equal to given number | Time Complexity => O(n)
18. Find common elements In 3 sorted arrays | Time Complexity => O(n1 + n2 + n3)
19. Rearrange the array in alternating positive and negative items with O(1) extra space | Time Complexity => O(nlogn) | Aux Space => O(1)
20. Find if there is any subarray with sum equal to 0 | Time Complexity => O(n)

1. Reverse a string
2. Check whether a string is Palindrome on not
3. Find duplicate characters in a String
4. Write a code to check whether one string is rotation of another
5. WAP to check whether a string is valid shuffle of two strings or not
6. Count and Say problem
7. WAP to find the longest Palindrome in a string (Longest Palindromic substring)
8. Find longest recurring subsequence in a string
9. Print all subsequences of a String

1. Search an element in a Matrix (Search in 2D Matrix)

1. Search in a rotated sorted array