GeeksforGeeks

Given an array A[] consisting 0s, 1s and 2s, write a function that sorts A[]. The functions should put all 0s first, then all 1s and all 2s in last.

You are given an array of n+2 elements. All elements of the array are in range 1 to n. And all elements occur once except two numbers which occur twice. Find the two repeating numbers.

Given an array A[], write a function that segregates even and odd numbers. The functions should put all even numbers first, and then odd numbers.

Given an array arr[] of n integers, construct a Product Array prod[] (of same size) such that prod[i] is equal to the product of all the elements of arr[] except arr[i]. Solve it without division operator and in O(n).

Given a sorted array and a value x, the ceiling of x is the smallest element in array greater than or equal to x, and the floor is the greatest element smaller than or equal to x. Assume than the array is sorted in non-decreasing order. Write efficient functions to find floor and ceiling of [...]

For example, if the input arrays are:
arr1[] = {1, 3, 4, 5, 7}
arr2[] = {2, 3, 5, 6}
Then your program should print Union as {1, 2, 3, 4, 5, 6, 7} and Intersection as {3, 5}.

Given an array arr[] of integers, find out the difference between any two elements such that larger element appears after the smaller number in arr[].

Given a binary matrix, find out the maximum size square sub-matrix with all 1s.
For example, consider the below binary matrix.

Asked by geek4u
Question: Write an efficient program for printing k largest elements in an array. Elements in array can be in any order.

Asked by kapil.
You are given an array of 0s and 1s in random order. Segregate 0s on left side and 1s on right side of the array. Traverse array only once.

Write a C function to return minimum and maximum in an array. You program should make minimum number of comparisons.

Question: Write a C function to find if a given integer appears more than n/2 times in a sorted array of n integers.

Asked by Vikas
Question: Write an efficient C program to find smallest and second smallest element in an array.
Difficulty Level: Rookie

Asked by Vineet
Question: An Array of integers is given, both +ve and -ve. You need to find the two elements such that their sum is closest to zero.
For the below array, program should print -80 and 85.

Inversion Count for an array indicates – how far (or close) the array is from being sorted. If array is already sorted then inversion count is 0. If array is sorted in reverse order that inversion count is the maximum.

Asked By Binod

Write a program to print all the LEADERS in the array. An element is leader if it is greater than all the elements to its right side. And the rightmost element is always a leader. For example int the array {16, 17, 4, 3, 5, 2}, leaders are 17, 5 and 2.

Asked by SG. ..
Question: Given an array all of whose elements are positive numbers, find the maximum sum of a subsequence with the constraint that no 2 numbers in the sequence should be adjacent in the array. So 3 2 7 10 should return 13 (sum of 3 and 10) or 3 2 5 10 [...]

Write a function rotate(ar[], d, n) that rotates arr[] of size n by d elements.

Write a function rotate(arr[], d, n) that rotates arr[] of size n by d elements.