Add some exercises for 11 section

c_modern_approach/Pointers/exercises/e_4.c

@@ -0,0 +1,22 @@
+#include <stdio.h>
+
+/**
+ * @brief Variable swapping exercide
+ */
+void swap(int *p, int *q) {
+  printf("*p: %d; p = %p\n", *p, p);
+  printf("*q: %d; q = %p\n", *q, q);
+  int x = *p;
+  int y = *q;
+  *p = y;
+  *q = x;
+}
+
+int main() {
+  int a, b;
+  a = 4;
+  b = 5;
+  printf("a = %d, b = %d\n", a, b);
+  swap(&a, &b);
+  printf("a = %d, b = %d", a, b);
+}

c_modern_approach/Pointers/exercises/e_5.c

@@ -0,0 +1,35 @@
+#include <stdio.h>
+
+/* Splitting seconds into hh:mm:ss */
+
+void split_time(long total_sec, int *hr, int *min, int *sec) {
+  int f_h, f_m, f_s;
+  f_h = total_sec / 3600;
+  printf("hours: %d\n", f_h);
+  total_sec = total_sec - f_h * 3600;
+  f_m = total_sec / 60;
+  printf("minutes: %d\n", f_m);
+  total_sec = total_sec - f_m * 60;
+  printf("seconds: %ld\n", total_sec);
+  *hr = f_h;
+  *min = f_m;
+  *sec = total_sec;
+}
+
+void split_time_otimized(long total_sec, int *hr, int *min, int *sec) {
+  *hr = (int)(total_sec / 3600);
+  *min = (int)((total_sec % 3600) / 60);
+  *sec = (int)(total_sec % 60);
+}
+
+int main() {
+  long total_sec = 5123;
+  int hours, minutes, seconds;
+  hours = 0;
+  minutes = 0;
+  seconds = 0;
+  printf("BEFORE: %d:%d:%d\n", hours, minutes, seconds);
+  /* split_time(total_sec, &hours, &minutes, &seconds); */
+  split_time_otimized(total_sec, &hours, &minutes, &seconds);
+  printf("AFTER: %d:%d:%d\n", hours, minutes, seconds);
+}

c_modern_approach/Pointers/exercises/e_6.c

@@ -0,0 +1,43 @@
+/* Finding two largest values in array */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+
+#define MAX_RANDOM_VALUE 1000
+#define ARRAY_SIZE 10
+
+void find_two_largest(int a[], int n, int *largest, int *second_largest) {
+  for (int i = 0; i < n; i++) {
+    if (a[i] > *largest) {
+      *second_largest = *largest;
+      *largest = a[i];
+    } else if (a[i] < *largest && a[i] > *second_largest) {
+      *second_largest = a[i];
+    }
+  }
+}
+
+int main() {
+  int random_numbers_array[ARRAY_SIZE];
+  int largest = 0;
+  int second_largest = 0;
+  // Generate random numbers
+  srand(time(NULL));
+  for (int i = 0; i < ARRAY_SIZE; i++) {
+    random_numbers_array[i] = rand() % MAX_RANDOM_VALUE + 1;
+  }
+  // Print array
+  printf("[");
+  for (int i = 0; i < ARRAY_SIZE; i++) {
+    if (i == ARRAY_SIZE - 1) {
+      printf("%d", random_numbers_array[i]);
+    } else {
+      printf("%d,", random_numbers_array[i]);
+    }
+  }
+  printf("]\n");
+  // Exercise
+  find_two_largest(random_numbers_array, ARRAY_SIZE, &largest, &second_largest);
+  printf("Largest: %d\nSecond largest: %d\n", largest, second_largest);
+}