while (1) { printf("\n===== Library Management System =====\n"); printf("1. Add Book\n"); printf("2. Display Books\n"); printf("3. Search Book by ID\n"); printf("4 ...

/* Book structure */ typedef struct { int id; // unique book id char title[MAX_STRING]; char author[MAX_STRING]; char publisher[MAX_STRING]; int quantity; // total copies available in library } Book; ...