implement recursive and iterative functions to count character

count_char.c

@@ -22,12 +22,26 @@ until the end of the string ('\0').
 
 */
 
-// TODO: the recursive implementation
 int count_char_recursive(const char* str, char c) {
-    return 0;
+    if (str[0] == '\0') {
+        return 0;
+    }
+
+    // skips the first character by moving the pointer to the next character
+    char* truncated = str + 1;
+
+    // true is 1, false is 0. no need to write a ternary operator
+    return (str[0] == c) + count_char_recursive(truncated, c);
 }
 
-// TODO: the iterative implementation
 int count_char_iterative(const char* str, char c) {
-    return 0;
+    int sum = 0;
+
+    for(int i = 0; str[i] != '\0'; i++) {
+        if (str[i] == c) {
+            sum++;
+        }
+    }
+
+    return sum;
 }