China Cat my RAM

Subset Sum ^{with a negative number}

Problem:
Given a sorted array say int num[10]={-5,1,6,7,9,9,20,25,31,45}, write a function void findsum(int [],int x) that can print out all possible pair of elements in array that can make a sum equal to x. For example if value of x is 26, then function should print {1,25}, {25,1}, {-5,31}, {31,-5}.

private static void findSumFunction() {

    //The problem provided me with an already-sorted array
	final int[] testData = new int[]{-5,1,6,7,9,9,20,25,31,45};

	final int X = 26;

    /*first task is to loop through original sorted array and find out where
    * searching can stop. If x = 26, then searching can stop once you get
    * to numbers > 26 EXCEPT for the fact that there are negative number(s)
    * in the test data.
    * So first, find out what the lowest number is. If it is negative, adding a
    * simple calculation to the algorithm will handle it.
    * find lowest number to see if there is a negative number, this is O(1)
    */
	if (testData[0] < lowestNumber) {
		lowestNumber = testData[0];
	}
	System.out.println("lowestNumber is " + lowestNumber);

    //1st go through array backward & stop before any value + negative num > X
    //because those elem(s) are not needed. Worst case, this is O(n)
	int rightIndex = testData.length - 1;
	while (testData[rightIndex] + lowestNumber > X) {
		int answer = testData[rightIndex] + lowestNumber;
		System.out.println("don't need " + answer);
		rightIndex--;
	}

	//Now go through the array frontward.Never go past rightIndex
	//Simultaneously I am going through the array frontward and backward
	int leftIndex = 0;
	while (leftIndex < rightIndex) {
		if (testData[leftIndex] + testData[rightIndex] == X) {
			System.out.println(testData[leftIndex] + " + " + testData[rightIndex]);
			leftIndex++;
			rightIndex--;
		}
		else if (testData[leftIndex] + testData[rightIndex] < X) {
			leftIndex++;
		}
		else {
			rightIndex--;
		}
	}
}