| 1 | #include <stdio.h> |
| 2 | #include <stdbool.h> |
| 3 | |
| 4 | /** Display a prompt to the user then wait for an integer input. */ |
| 5 | int promptValue(const char* prompt) { |
| 6 | printf("%s:\n", prompt); |
| 7 | int result; |
| 8 | scanf("%d", &result); |
| 9 | return result; |
| 10 | } |
| 11 | |
| 12 | void displayMenuEntry(int index, const char* label) { |
| 13 | printf("%d | %s\n", index, label); |
| 14 | } |
| 15 | |
| 16 | void displayMenu() { |
| 17 | displayMenuEntry(1, "Addition"); |
| 18 | displayMenuEntry(2, "Substraction"); |
| 19 | displayMenuEntry(3, "Multiplication"); |
| 20 | displayMenuEntry(4, "Exit"); |
| 21 | } |
| 22 | |
| 23 | /** Prompt the user for his operation choice. |
| 24 | * |
| 25 | * @return The selected operation. No invalid value can be returned. |
| 26 | */ |
| 27 | int promptOperation() { |
| 28 | displayMenu(); |
| 29 | int result; |
| 30 | |
| 31 | do { |
| 32 | result = promptValue("Choose an option"); |
| 33 | |
| 34 | if (result >= 1 && result <= 4) { |
| 35 | break; |
| 36 | } |
| 37 | |
| 38 | puts("Please choose a valid option (1-4)"); |
| 39 | } while (true); |
| 40 | |
| 41 | return result; |
| 42 | } |
| 43 | |
| 44 | int main() { |
| 45 | int operation = promptOperation(); |
| 46 | |
| 47 | if (operation == 4) { |
| 48 | return 0; |
| 49 | } |
| 50 | |
| 51 | int initialValue = promptValue("Initial value"); |
| 52 | |
| 53 | do { |
| 54 | int nextValue = promptValue("Next value"); |
| 55 | |
| 56 | if (nextValue == 0) { |
| 57 | break; |
| 58 | } |
| 59 | |
| 60 | switch (operation) { |
| 61 | // Addition |
| 62 | case 1: |
| 63 | initialValue += nextValue; |
| 64 | break; |
| 65 | |
| 66 | // Substraction |
| 67 | case 2: |
| 68 | initialValue -= nextValue; |
| 69 | break; |
| 70 | |
| 71 | // Multiplication |
| 72 | case 3: |
| 73 | initialValue *= nextValue; |
| 74 | break; |
| 75 | } |
| 76 | |
| 77 | printf("Result: %d\n", initialValue); |
| 78 | } while (true); |
| 79 | } |