Finding the numbers in Array for Given Sum

import java.util.Arrays;

import java.util.HashMap;

import java.util.Map;

public class LocalTest {

// Finding sum of two numbers using O(n2)

public static int[] getSum(int arra[], int sum) {

for (int i = 0; i < arra.length; i++) {

for (int j = 0; j < arra.length; j++) {

if (arra[i] + arra[j] == sum) {

return new int[] { arra[i], arra[j] };

}

}

}

return null;

}

//Finding sum of two numbers using O(n)

public static int[] findSum(int arra[], int sum) {

Map<Integer, Integer> arraryMap = new HashMap<Integer, Integer>();

for (int i = 0; i < arra.length; i++) {

int value = arra[i];

if (arraryMap.containsKey(sum - value)) {

return new int[] { arra[arraryMap.get(sum - value)], arra[i]  };

}

arraryMap.put(value, i);

}

return null;

}

public static void main(String[] args) {

int arrValues[] = {2,5,7,9,11,3,8 };

System.out.println(Arrays.toString(getSum(arrValues,13)));

System.out.println(Arrays.toString(findSum(arrValues,13)));

}

}

Output

[2, 11]

[2, 11]

Thanks for your valuable comments

Interview Questions Part 1

• ·         Traverse a binary tree
• ·         Reverse every k-element in a linked list
• ·         Find the combination of elements with sum as N.
• ·         Find the duplicates in Linked List
• ·         Print binary tree in level order
• ·         Validation of parenthesis in string (Total number should be equal for “(“ and “)”  )
• ·         Swap the nodes in binary tree.
• ·         Print Binary tree in pre order/post order/ inorder
• ·         Stack operations using O(1)
• ·         Implement Queue Using Linked List
• ·         Merge Sort implementation.
• ·         How to find the linked list is circular or not.
• ·         Find the repeated values in String.