Add Prime Number in Dart (TheRenegadeCoder#4976)

Author: gangaasoonu

archive/d/dart/prime-number.dart

@@ -0,0 +1,35 @@
+// Issue 4970
+import 'dart:math';
+void main(List<String> args){
+  const String error_message= "Usage: please input a non-negative integer";
+  if (args.isEmpty){
+    print(error_message);
+    return;
+  }
+  try{
+    int num_needed = int.parse(args[0]);
+    if (num_needed.isNegative){
+      print(error_message);
+      return;
+    }
+
+    // If the number is even number other than 2 OR if number is either 0 or 1, Print Composite
+    if( (num_needed == 0)|| (num_needed == 1) || (num_needed %2 ==0 && num_needed != 2) ){
+      print("Composite");
+      return;
+    }
+    bool is_prime = true;    
+    int max_divisor = sqrt(num_needed).toInt();
+    for (int i_index = 3; i_index <= max_divisor; i_index +=2){
+      if(num_needed % i_index == 0){
+        is_prime = false;
+        break;
+      }
+    }
+
+    print(is_prime ? "Prime" : "Composite");
+  }
+  catch(e){
+    print(error_message);
+  }
+}