did this not have indentation?

huh?

main.cpp

@@ -1,4 +1,3 @@
-
 // Generate primes using the sieve of eratosthenes
 #include <iostream>
 #include <vector>
@@ -15,8 +14,8 @@ int main() {
     notprime = false;
     for (unsigned int i=0;i<primes.size();++i) {
       if (nextnumber % primes[i] == 0) {
-	notprime = true;
-	break;
+	      notprime = true;
+	      break;
       }
     }
     if (!notprime) {