added TwoPointersAlgo

Others/TwoPointersAlgo.java

@@ -0,0 +1,73 @@
+import java.util.*;
+import java.lang.*;
+import java.io.*;
+
+class TwoPointersAlgo {
+    //This function prints all pairs in the array that sum to a number X. If no such pair exists then output will be -1.
+	static void twoSum(int A[], int X)
+    {
+        Arrays.sort(A);
+        
+        //Array sorting is necessary for this algo to function correctly
+        
+        int n = A.length;
+        int i = 0, j = n-1, flag=0;
+        //Implementation of the algorithm starts
+        while(i<j)
+        {
+            if(A[i]+A[j]==X)
+            {
+                System.out.println(A[i] + " " + A[j] + " " + X);
+                flag = 1;
+                i++;
+                j--;
+            }
+            else if(A[i]+A[j]<X)
+            {
+                i++;
+            }
+            else j--;
+        }
+        
+        //Implementation ends
+        
+        if(flag==0)
+        System.out.println(-1);
+    }//end of function twoSum
+	public static void main (String[] args) {
+		Scanner in = new Scanner(System.in);
+		int t,n;
+		t = in.nextInt();
+		//for number of test cases
+		while(t>0)
+		{
+		    t--;
+		    n = in.nextInt();
+		    int a[] = new int[n];
+		    for(int i = 0; i<n; i++)
+		    {
+		        a[i] = in.nextInt();
+		    }
+		    //taking array input
+		    int k = in.nextInt(); //the total of the pair entered by the user
+		    twoSum(a, k);
+		    
+		}
+	}//end of main
+}//end of class
+
+/*Sample Input/Output
+Input:
+2
+7
+1 2 3 4 5 6 7
+98
+7
+1 2 3 4 5 6 7
+8
+Output:
+-1
+1 7 8
+2 6 8
+3 5 8
+*/