// // PerfectNum is a little program that checks if aa given Integer is a Perfect Number // (for the first 6 Perfect Numbers: 6, 28, 496, 8128, 33550336, 8589869056) // // Created by Ronen Gil on 11/10/2018. // #include #include using namespace std; unsigned long int Deviders[40]; unsigned long int* deviders(unsigned long int); bool isPerfect(unsigned long int); int main(int argc, const char * argv[]) { const unsigned long int anInt = sizeof(anInt); string input = " "; bool flag = false; unsigned long num, i; cout << "A Perfect Number is a number that equals to the some of all it\'s hole deviders, excluding the number itself." << endl; cout << "For example: 6 = 1 + 2 + 3 or 28 = 1 + 2 + 4 + 7 + 14." << endl; // cout << "You can find more info at: https://en.wikipedia.org/wiki/Perfect_number" << endl; cout << "You can use this program to test if a hole positive Number is a Perfect Number (for the first 6 Perfect Numbers)." << endl << endl; while (!flag || input == "0") // Let's make sure we have an integer greater then 0. This loop doesn't work in this playground! { cout << "Enter a hole number between 1 and 200000000000:" << endl; cin >> input; switch (input[0]) { // The first character. case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': flag = true; break; default: flag = false; break; } for (i = 1; i < input.size(); i++) // a loop to iterate the hole input. { if (flag) // Only if the characters before are all digits { switch (input[i]) { // The rest of the input. case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': flag = true; break; default: flag = false; break; } } } if (!flag || input == "0") // there is a character in the input that is not a digit, or the input is "0". { cout << endl << input << " is NOT a hole number between 1 and 200000000000!" << endl; } } num = stoul(input); // We have an integer. cout << endl << endl << num << " is"; fill(Deviders, Deviders+sizeof(Deviders)/anInt, 0); // Reinit the deviders array with '0's. deviders(num); // Let's see what devides the Integer with no remainder. isPerfect(num) ? cout << " ": cout << " NOT "; // Add the rweminers together and see if we have a Perfect Number. cout << "a Perfect Number!" << endl; if (isPerfect(num)) // We have a Perfect Number. Let's print out it's deviders. { cout << "It\'s deviders are: 1, "; for (i = 0; Deviders[i] != 0; i++) { cout << Deviders[i]; if (Deviders[i + 1] != 0) cout << ", "; } cout << "." << endl; } return 0; } unsigned long int* deviders(unsigned long int num) { unsigned long int i, j; for (i = 2, j = 0; i<= num / 2; i++) { if ((num % i) == 0) { Deviders[j] = i; j++; } } return Deviders; } bool isPerfect(unsigned long int num) { bool isperfect = false; unsigned long int i, j; for (i = 0, j = 1; Deviders[i] != 0; i++) { j += Deviders[i]; } if ( j == num) isperfect = true; return isperfect; }

Perfect Number.cpp