diff --git a/LinearSearch.java b/LinearSearch.java
new file mode 100644
index 0000000..58ae653
--- /dev/null
+++ b/LinearSearch.java
@@ -0,0 +1,28 @@
+package Array;
+
+import java.util.Scanner;
+
+public class LinearSearch {
+
+	public static void main(String[] args) {
+		try(Scanner sc = new Scanner(System.in)){;
+		int n = sc.nextInt();
+		int arr[]= new int[n];
+		for(int i = 0; i<n; i++) {
+			arr[i]= sc.nextInt();
+		}
+		int a=sc.nextInt();
+		int j;
+		for(j =0; j<n; j++) {
+			if(a == arr[j]) {
+				System.out.println(j);
+				break;
+			}
+		}
+		if(j==n) {
+			System.out.println("-1");
+		}
+	}
+
+}
+}
\ No newline at end of file
diff --git a/PairSum.java b/PairSum.java
new file mode 100644
index 0000000..2257595
--- /dev/null
+++ b/PairSum.java
@@ -0,0 +1,28 @@
+package Array;
+
+import java.util.Scanner;
+
+public class PairSum {
+
+	public static void main(String[] args) {
+		Scanner sc = new Scanner(System.in);
+		int n = sc.nextInt();
+		int arr[]= new int[n];
+		for(int i = 0; i<n; i++) {
+			arr[i]=sc.nextInt();
+		}
+		int x = sc.nextInt();
+		int a = 0;
+		for(int i = 0; i<n; i++) {
+			for(int j = 0; j<n; j++) {
+				if(i!=j) {
+				if(arr[i]+arr[j]==x) {
+					a=a+1;
+				}
+				}
+			}
+		}
+		System.out.println(a/2);
+	}
+
+}
diff --git a/SwapAlternate.java b/SwapAlternate.java
new file mode 100644
index 0000000..4ff65de
--- /dev/null
+++ b/SwapAlternate.java
@@ -0,0 +1,37 @@
+package Array;
+
+import java.util.Scanner;
+
+public class SwapAlternate {
+
+	public static void main(String[] args) {
+		try (Scanner sc = new Scanner(System.in)) {
+			int temp = 0;
+			int n = sc.nextInt();
+			int arr[]= new int[n];
+			for(int i =0; i< n; i++) {
+				arr[i]=sc.nextInt();
+			}
+			if(n%2==0) {
+				for(int i = 0; i<n; i=i+2) {
+					temp = arr[i];
+					arr[i]=arr[i+1];
+					arr[i+1]=temp;
+				}
+			}
+			else {
+				for(int i = 0; i<n-1; i=i+2) {
+					temp = arr[i];
+					arr[i]=arr[i+1];
+					arr[i+1]=temp;
+			}
+			
+			}
+			for(int i = 0; i<n; i++) {
+			System.out.print(arr[i]+" ");
+			}
+		}
+
+	}
+
+}