TP_7_C/exo2-extra.c

   1 #include <stdio.h>
   2 #include <stdbool.h>
   3 #include <stdlib.h>
   4
   5 /** Pointer to a function with this profile */
   6 typedef int(*operation_cb)(int v1, int v2);
   7
   8 /** Describe a single operation */
   9 typedef struct {
  10     const char* label;
  11     operation_cb cb;
  12 } operation_t;
  13
  14 int doAddition(int v1, int v2);
  15 int doSubstraction(int v1, int v2);
  16 int doMultiplication(int v1, int v2);
  17 int doXOR(int v1, int v2);
  18
  19 /** All available operations */
  20 operation_t operations[4] = {
  21     {
  22         "Addition",
  23         doAddition
  24     },
  25     {
  26         "Substraction",
  27         doSubstraction
  28     },
  29     {
  30         "Multiplication",
  31         doMultiplication
  32     },
  33     {
  34         "XOR",
  35         doXOR
  36     }
  37 };
  38 #define operations_count ((int) (sizeof(operations) / sizeof(operations[0])))
  39
  40 /** Display a prompt to the user then wait for an integer input. */
  41 void promptValue(const char* prompt, int* value) {
  42     printf("%s:\n", prompt);
  43     scanf("%d", value);
  44 }
  45
  46 void displayMenuEntry(int index, const char* label) {
  47     printf("%d | %s\n", index, label);
  48 }
  49
  50 /** Display all available operations and an EXIT option. */
  51 void displayMenu() {
  52     for (int menuIndex = 0; menuIndex < operations_count; ++menuIndex) {
  53         displayMenuEntry(menuIndex + 1, operations[menuIndex].label);
  54     }
  55
  56     displayMenuEntry(operations_count + 1, "Exit");
  57 }
  58
  59 /** Prompt the user for his operation choice.
  60  *
  61  * @return The selected operation. If the exit option is chosen, return NULL
  62  */
  63 operation_t* promptOperation() {
  64     displayMenu();
  65
  66     do {
  67         int result;
  68         promptValue("Choose an option", &result);
  69
  70         if (result == (operations_count + 1)) {
  71             return NULL;
  72         }
  73
  74         if (result >= 1 && result <= operations_count) {
  75             return &operations[result - 1];
  76         }
  77
  78         printf("Please choose a valid option (1-%d)\n", operations_count);
  79     } while (true);
  80 }
  81
  82 int doAddition(int v1, int v2) {
  83     return v1 + v2;
  84 }
  85
  86 int doSubstraction(int v1, int v2) {
  87     return v1 - v2;
  88 }
  89
  90 int doMultiplication(int v1, int v2) {
  91     return v1 * v2;
  92 }
  93
  94 int doXOR(int v1, int v2) {
  95     return v1 ^ v2;
  96 }
  97
  98 int main() {
  99     operation_t* operation = promptOperation();
 100
 101     if (operation == NULL) {
 102         return 0;
 103     }
 104
 105     int initialValue;
 106     promptValue("Initial value", &initialValue);
 107
 108     do {
 109         int nextValue;
 110         promptValue("Next value", &nextValue);
 111
 112         if (nextValue == 0) {
 113             break;
 114         }
 115
 116         initialValue = operation->cb(initialValue, nextValue);
 117         printf("Result: %d\n", initialValue);
 118     } while (true);
 119 }