private void button4_Click_1(object sender, EventArgs e)
{
//http://www.careercup.com/question?id=5772881111810048
//http://stackoverflow.com/questions/5534063/zero-sum-subarray
/* ex: 2 3 -4 9 -1 -7 -5 6 5
* sum to enter in hash table : 0 2 5 1 10 9 2 -3 3 8
* index to enter in hash table: -1 0 1 2 3 4 5 6 7 8
* Logic:
* 1) Create an ht with sum as key and list of index as value
* 2) we add the base value in the ht as sum 0 and index -1 because if we encounter 0 in the iteration then we found the subarray of value 0
* 3) We iterate the given array from 0 to array.length -1
* 4) In the iteration we make the sum of the previous elements with the current element and use the sum as the key to ht
* 5) If the ht does not contain the sum. add sum as the key and value as the index (index list)
* 6) If the ht contains the sum, then we found the subarray having the value of zero
* grab the index of the sum in the ht with ht[sum]. The index sum and the current item sum is equla to 0 so that mean the items from index + 1 to current index sum will be zero
* print the values from index + 1 to current index
* The reason we have List<int> as value is we might have multiple sum value so each key might have multiple indexes like below
* int[] array = {0, 1, -1, 0} we need to print every subarray the can cause the sum to 0 eg (0) (1,-1) (0,1,-1) etc
*
*
*/
int[] input = AlgorithmHelper.ConvertCommaSeparetedStringToInt(this.textBox6.Text);
List <string> result = FindSubArraySumOfzero(input);
this.textBox5.Text = AlgorithmHelper.ConvertStringListArrayToSpaceSeparatedString(result);
}
