Adding is_prime function with tests

isprime.cpp

@@ -0,0 +1,63 @@
+#include <iostream>
+#include <climits>
+#include <cmath> 
+
+/* Update if you are testing more
+ * Assuming 
+ */
+#define TESTS 7
+#define TEST_INPUTS {-128,	\
+		0,  		\
+		1,		\
+		2, 		\
+		45,		\
+		101,		\
+		127}
+
+#define EXPECTED_OUTPUT {false,	\
+		false,		\
+		false,		\
+		true,		\
+		false,		\
+		true,		\
+		true}
+
+using namespace std;
+
+/* is_prime checks whether the number is prime and returns true for any prime
+ * and positive integer and returns false for any other condition
+ */
+
+bool is_prime(long n) {
+	if(n <= 1) return false;
+	long test = sqrt(n), i = 0;
+	for(i = test; i > 1; i--){
+		if((n % i) == 0) return false;
+	}	
+	return true;
+}
+
+/* prime_tester unit tests the is_prime for a set of inputs mentioned at the
+ * top
+ */
+
+void prime_tester(void) {
+	bool expected[TESTS] = EXPECTED_OUTPUT;
+	long inputs[TESTS] = TEST_INPUTS;
+	int i = 0;
+	for(i = 0; i < TESTS; i++){
+		if(expected[i] == is_prime(inputs[i])) {
+			cout<<"Test "<<i<<": Passed! Input: "<<inputs[i]<<endl;
+		} else {
+			cout<<"Test "<<i<<": Failed! Failing input: "<<inputs[i]<<endl;
+		}		
+	}
+}
+
+
+/* Uncomment to test the code*/
+//int main(void) {
+//	prime_tester();
+//	return 0;
+//}
+