Added Swap two strings

C++ program/swap_two_string.cpp

@@ -0,0 +1,23 @@
+#include <iostream>
+
+#include <cstring> //string library
+
+using namespace std;
+
+int main() {
+    int n; //length of string
+    cin>>n;
+    char s1[n];
+    char s2[n];
+    char s3[n]; //temporary string
+    //Input String 1
+    cin>>s1;
+    //Input String 2
+    cin>>s2;
+    strcpy(s3,s1); //copy contents of s1 in s3
+    strcpy(s1,s2);  // similar to  s1=s2
+    strcpy(s2,s3);
+    cout<<s1<<"\n";
+    cout<<s2;
+    return 0;
+}