【420】链表实现Quack
quack.h
// quack.h: an interface definition for a queue/stack #include <stdio.h> #include <stdlib.h> typedef struct node *Quack; Quack createQuack(void); // create and return Quack void push(int, Quack); // put the given integer onto the top of the quack void qush(int, Quack); // put the given integer onto the bottom of the quack int pop(Quack); // pop and return the top element on the quack int isEmptyQuack(Quack); // return 1 is Quack is empty, else 0 void makeEmptyQuack(Quack);// remove all the elements on Quack void showQuack(Quack); // print the contents of Quack, from the top down
quackLL.c
// quackLL.c: a linked-list-based implementation of a quack #include "quack.h" #include <limits.h> // INT_MAX means largest int // if using this value, you need to include <limits.h> #define HEAD_DATA INT_MAX // dummy data struct node { int data; struct node *next; }; // create a null head Quack createQuack(void) { // Actually this head is NULL, it doesn't store // meaningful data, only store the address. Quack head; head = malloc(sizeof(struct node)); if (head == NULL) { fprintf(stderr, "Out of memory\n"); exit(1); } head->data = HEAD_DATA; head->next = NULL; // return the address of head return head; } // push a new node between head and 1st node void push(int data, Quack qs) { Quack newnode; // determine whether this quack is NULL or not if (qs == NULL) { fprintf(stderr, "push: quack not initialised\n"); } else { newnode = malloc(sizeof(struct node)); if (newnode == NULL) { fprintf(stderr, "push: no memory, aborting\n"); exit(1); } newnode->data = data; newnode->next = qs->next; qs->next = newnode; } return; } // pop the 1st node int pop(Quack qs) { // store data in variable retval int retval = 0; if (qs == NULL) { fprintf(stderr, "pop: quack not initialised\n"); } else { // if qs is empty, you can't pop any nodes if (isEmptyQuack(qs)) { fprintf(stderr, "pop: quack underflow\n"); } else { Quack pop_node = qs->next; retval = pop_node->data; // link head with 2nd node qs->next = qs->next->next; free(pop_node); pop_node = NULL; } } return retval; } // pop all nodes in qs void makeEmptyQuack(Quack qs) { if (qs == NULL) { fprintf(stderr, "makeEmptyQuack: quack not initialised\n"); } else { while (!isEmptyQuack) { pop(qs); } } return; } // only head, head link to NULL int isEmptyQuack(Quack qs) { if (qs == NULL) { fprintf(stderr, "makeEmptyQuack: quack not initialised\n"); } else { if (qs->next == NULL) { return 1; } } return 0; } // print all nodes void showQuack(Quack qs) { if (qs == NULL) { fprintf(stderr, "makeEmptyQuack: quack not initialised\n"); } else { // ??? maybe head is corrupted by opertions if (qs->data != HEAD_DATA) { fprintf(stderr, "showQuack: linked list head corrupted\n"); } else { printf("Quack: "); if (qs->next == NULL) { printf("<< >>\n"); } else { printf("<<"); Quack node = qs->next; while (node->next != NULL) { printf("%d ", node->data); node = node->next; } printf("%d ", node->data); printf(">>\n"); } } } return; }
clientQuack.c
#include "quack.h" int main() { Quack qs = createQuack(); push(1, qs); showQuack(qs); push(2, qs); showQuack(qs); push(3, qs); showQuack(qs); push(4, qs); showQuack(qs); pop(qs); showQuack(qs); pop(qs); showQuack(qs); pop(qs); showQuack(qs); pop(qs); showQuack(qs); }
运行下面命令实现编译
alex@ubuntu:Day01$ gcc quackLL.c clientQuack.c && ./a.out Quack: <<1 >> Quack: <<2 1 >> Quack: <<3 2 1 >> Quack: <<4 3 2 1 >> Quack: <<3 2 1 >> Quack: <<2 1 >> Quack: <<1 >> Quack: << >>