Beginner
1. Arithmetic Progression2. Geometric Progression3. Harmonic Progression4. No of triangles 5. Area of Polygon6. Trailing Zeros7. Min Platforms 8. Trapping Rain 9. Jump numbers10. Segregation of 0’s and 1’s11. Two SUM12. Triplet sum 13. Diagonal Sum14. Addition of two matrixes15. Subtraction of two matrixes16. Multiplication of two matrixes17. Transpose of given array18. Spiral Matrix19. Most Frequent Element20. Majority Element 21. Max difference 22. Odd occurring23. Second Largest and Second Smallest24. Next greater number25. Count Unique Elements26. Common elements 27. Removing Duplicates28. Balanced Array29. Rotating Array by k times30. Reverse Array31. Wave Array32. Merge arrays 33. Constraint Sort34. Find element in Sorted rotated array35. Sub Array Sum36. Largest subarray of 0’s and 1’s 37. K-Sub Array38. Max subarray sum39. Contiguous Square SumOdd occurring
LEVEL:Beginner
Description
Given an array of integers. You have to find the elements which occurred odd number of times. There should be at least one occurrence in the given array.
Input Format
First line contains the size of the array. Next line contains the n integers separated by the spaces.
Output Format
Elements whose occurred in odd number of times
5 1 1 1 1 1
1
3 1 2 2
1
6 2 5 5 4 1 3
2 4 1 3
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Approach
Approach1: Using HashMap
Step-i) Initialize a empty Hashmap and an ArrayList.
Step-ii) Iterate the array and take every element as a.
Step-iii) If a is not present in the hashmap, intialize a in hashmap as 0
Step-iv) If a is already present increase it’s value by 1.
Step-v) Now the hash map is of frequency of every element.
Step-vi) Iterate the hashmap and check the value of every element is odd or not.
Step-vii) If it is odd, add into the array list.
Step-ix) Return the ArrayList.
Time Complexity: O(N)
Space Complexity: O(N)
Note :
Let us know if you can come up with a better approach, mail us at support@theinquisitive.in Your approach will be reviewed and posted with credits to you.
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