Tag Archives: Java

Remove Duplicates From Sorted Array

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Given a sorted array, we have to write a code to remove the duplicates in-place such that each element appear only once and return the new length.

For this problem, we don’t have to use extra space. As we have to remove duplicates in-place (In O(1)).

Note that we have to return the new length, make sure to change the original array as well in place

For example:

Input : { 1, 2, 2, 3, 4, 4, 5, 6, 6, 7 }

Output: 7

Our function should return length 7 with first seven elements of array are {1, 2, 3, 4, 5, 6, 7}. It doesn’t matter what you leave beyond the returned length

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Subarray with Given Sum

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Find subarray with given sum.

Given an array of unsorted integers (Positive integers), We have to write a code to find a subarray whose sum is equal to a given sum.

We have to return subarray indexes (start and end index).

For Example –

  Example 1 :

Input : arr = {10, 2, 4, 7, 5}, sum = 13

Output: {1, 3}

The numbers present from the 1st to 3rd indexes are 2, 4, 7. When we add (2 + 4 + 7) it is 13.

Example 2 :

Input : arr = {1, 4, 20, 3, 10, 5}, sum = 33

  Output: {2, 4}

Example 3 :

  Input : arr = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, sum = 15

   Output: {0, 4}

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Find All Duplicates in an Array

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How to find all duplicates in an array without using extra space?

Given an array of integers, the integers are in the range of 1 ≤ a[i] ≤ n (n = size of array). In this Array, some elements appear twice and others appear once.

Find all the elements that appear twice in this array.

We have to solve this problem without using extra space and in O(n) time complexity.

For Example:

Input: [4, 3, 2, 7, 8, 2, 3, 1]

Output: [2, 3]

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