Added more efficiencies

RountreeLabs/Lab01/isPrime.c

@@ -1,21 +1,27 @@
+#include <time.h>
 #include <stdio.h>
 #include <stdlib.h>
 
 int is_prime(int n){
 	int i;
-	for(i=2;i<n;i++){
+	for(i=3; i<((n/2)+1);i++){
 		if(n%i == 0){
 			return 0;
 		}	
+	i++;
 	}
 	return 1;
 }
 int main(void){
+	clock_t se, ss;
 	int n = 2;
-	for (n = 2; n < 100; n++){
+	ss = clock();
+	for (n = 2; n < 100000; n++){
 		if(is_prime(n)){
 			printf("%d\n", n);
 		}
 	}
+	se = clock();
+	printf("Operation Time: %f\n", (se - ss)/(double)CLOCKS_PER_SEC);
 	return EXIT_SUCCESS;
-}	 
+}