Added reverse.dart

CONTRIBUTORS.md

@@ -12,6 +12,14 @@ About: I'm moslem programmer<br/>
 Programming Language: Java, kotlin, flutter<br/>
 Email: [email protected]<br/>
 
+
+Name: [Jahnavi Gupta.](https://github.com/janvig)<br/>
+Place: Gandhinagar, India<br/>
+About: I'm pursuing BTech in ICT at DA-IICT<br/>
+Programming Language: Java, C, C++, MATLAB, dart<br/>
+Email: [email protected]<br/>
+
+
 Name: [Utkarsh Garg](https://github.com/utkarsh22garg)<br/>
 Place: Allahabad,India<br/>
 About: I'm pursuing 3rd year from MNNIT Allahbad<br/>

factorial/factorial.dart

@@ -0,0 +1,14 @@
+int factorial(int n)
+{
+ int fact=1;
+ for(int i=1;i<=n;i++)
+  fact=fact*i;
+  return fact;
+}
+void main()
+{
+  int fac=factorial(4);
+  print('factorial ${fac}');
+}
+
+

random number/random.java

@@ -0,0 +1,6 @@
+import java.util.Random;
+void main()
+{
+    Random rand = new Random();
+    int  n = rand.nextInt(50) + 1;
+ }

reverse/reverse.dart

@@ -0,0 +1,19 @@
+int reverse(int n)
+{
+ int rev=0;
+  while(n!=0)
+  {
+    int p=n%10;
+    int q=n-p;
+    rev=rev*10+p;
+    n= (q/10).floor();
+  }
+  return rev;
+
+}
+void main()
+{
+  int r=reverse(87852);
+  print('reverse ${r}');
+}
+