Two sum.

Given an array A[] and a number x, check for pair in A[] with sum as x

 

http://www.geeksforgeeks.org/write-a-c-program-that-given-a-set-a-of-n-numbers-and-another-number-x-determines-whether-or-not-there-exist-two-elements-in-s-whose-sum-is-exactly-x/

    public int[] twoSum(int[] numbers, int target) {

        // Start typing your Java solution below

        // DO NOT write main() function

        int[] r = {};

        if(numbers == null|| numbers.length == 0)

            return r;

        

        int n = numbers.length;

        

        r = new int[n];

        int count=0;

        int i =0,temp= 0;

        

        //set a large array.

        int[] binMap = new int[10000];

        

        for(i =0;i<n;i++)

        {

            temp = target-numbers[i];

            if(temp>=0 && (binMap[temp]==1))

            {

                r[count++]=numbers[i];

                r[count++]= temp;

            }

            binMap[numbers[i]] =1;

        }

        

        return r;

                

    }

}