Two sum #459

Programming/C#/Two sum

@@ -0,0 +1,86 @@
+
+
+using System;
+
+class twosum {
+	static bool hasArrayTwoCandidates(int[] A,
+					int arr_size, int sum)
+	{
+		int l, r;
+
+
+		sort(A, 0, arr_size - 1);
+
+
+		l = 0;
+		r = arr_size - 1;
+		while (l < r) {
+			if (A[l] + A[r] == sum)
+				return true;
+			else if (A[l] + A[r] < sum)
+				l++;
+			else // A[i] + A[j] > sum
+				r--;
+		}
+		return false;
+	}
+
+
+
+
+	static int partition(int[] arr, int low, int high)
+	{
+		int pivot = arr[high];
+
+
+		int i = (low - 1);
+		for (int j = low; j <= high - 1; j++) {
+
+			if (arr[j] <= pivot) {
+				i++;
+
+
+				int temp = arr[i];
+				arr[i] = arr[j];
+				arr[j] = temp;
+			}
+		}
+
+
+		int temp1 = arr[i + 1];
+		arr[i + 1] = arr[high];
+		arr[high] = temp1;
+
+		return i + 1;
+	}
+
+
+	static void sort(int[] arr, int low, int high)
+	{
+		if (low < high) {
+
+			int pi = partition(arr, low, high);
+
+
+			sort(arr, low, pi - 1);
+			sort(arr, pi + 1, high);
+		}
+	}
+
+
+	public static void Main()
+	{
+		int[] A = { 1, 4, 45, 6, 10, -8 };
+		int n = 16;
+		int arr_size = 6;
+
+		if (hasArrayTwoCandidates(A, arr_size, n))
+			Console.Write("Array has two elements"
+						+ " with given sum");
+		else
+			Console.Write("Array doesn't have "
+						+ "two elements with given sum");
+	}
+}
+
+