Category Archives: Algorithm

Sort elements by frequency | Set 1

Print the elements of an array in the decreasing frequency if 2 numbers have same frequency then print the one which came first. Examples: Input: arr[] = {2, 5, 2, 8, 5, 6, 8, 8} Output: arr[] = {8, 8, 8, 2, 2, 5, 5, 6} Input: arr[] = {2, 5, 2, 6, -1, 9999999,… Read More »

Median of two sorted arrays

Question: There are 2 sorted arrays A and B of size n each. Write an algorithm to find the median of the array obtained after merging the above 2 arrays(i.e. array of length 2n). The complexity should be O(log(n))

Ugly Numbers

Ugly numbers are numbers whose only prime factors are 2, 3 or 5. The sequence 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, … shows the first 11 ugly numbers. By convention, 1 is included. Given a number n, the task is to find n’th Ugly number. Input : n = 7… Read More »

8 queen problem

The eight queens problem is the problem of placing eight queens on an 8×8 chessboard such that none of them attack one another (no two are in the same row, column, or diagonal). More generally, the n queens problem places n queens on an n×n chessboard. There are different solutions for the problem. Backtracking |… Read More »