make stuff work

main.c

@@ -1,7 +1,94 @@
 #include <stdio.h>
+#include <stdbool.h>
+#include <string.h>
 
-int main(int argc, char **argv) { 
+#define MAX_TODO_TITLE_LENGTH 32
-  printf("Hello, world!\n");
+#define MAX_TODOS 10
 
-  return 0; 
+typedef struct {
+  char title[MAX_TODO_TITLE_LENGTH];
+  bool completed;
+} TodoItem;
+
+enum Command {
+  ADD = 'a',
+  MARK = 'm',
+  PRINT = 'p',
+  QUIT = 'q'
+};
+
+TodoItem create_todo(const char *title) {
+  TodoItem item;
+  strncpy(item.title, title, MAX_TODO_TITLE_LENGTH);
+  item.completed = false;
+  return item;
+}
+
+void mark_todo(TodoItem *item, bool completed) {
+  (*item).completed = completed;
+}
+
+void print_todo(TodoItem item) {
+  printf("%s - ", item.title);
+  if (item.completed) {
+    printf("Completed\n");
+  } else {
+    printf("Not Completed\n");
+  }
+}
+
+TodoItem todos[MAX_TODOS];
+int todos_count = 0;
+
+void add_todo() {
+  char title[MAX_TODO_TITLE_LENGTH];
+  printf("Enter todo title: ");
+  fgets(title, MAX_TODO_TITLE_LENGTH - 1, stdin);
+
+  TodoItem item = create_todo(title);
+  todos[todos_count] = item;
+  todos_count++;
+}
+
+void print_all_todos() {
+  for (int i = 0; i < todos_count; i++) {
+    print_todo(todos[i]);
+  }
+}
+
+int main(int argc, char **argv) {
+  char cmd;
+  int op_index = -1;
+  do {
+    printf("Enter command: ");
+    cmd = getc(stdin);
+    getc(stdin); // remove the newline character from the buffer
+
+    switch (cmd) {
+      case ADD:
+        if (todos_count + 1 > MAX_TODOS) {
+          printf("No more space for new todos\n");
+          break;
+        }
+        add_todo();
+        break;
+      case MARK:
+        do {
+          printf("Enter todo index: ");
+          op_index = getc(stdin) - '0';
+          getc(stdin); // remove the newline character from the buffer
+        } while (op_index < 0 || op_index >= todos_count);
+        mark_todo(&todos[op_index], !todos[op_index].completed);
+        break;
+      case PRINT:
+        print_all_todos();
+        break;
+      case QUIT:
+        break;
+      default:
+        printf("Invalid command\n");
+        break;
+    }
+
+  } while (cmd != QUIT);
 }