数据结构 - (3)栈的操作

一、栈(Stack)的介绍

栈（stack）又名堆栈，它是一种运算受限的线性表。限定仅在表尾进行插入和删除操作的线性表。这一端被称为栈顶，相对地，把另一端称为栈底。向一个栈插入新元素又称作进栈、入栈或压栈，它是把新元素放到栈顶元素的上面，使之成为新的栈顶元素；从一个栈删除元素又称作出栈或退栈，它是把栈顶元素删除掉，使其相邻的元素成为新的栈顶元素。

二、具体

1、添加相关头文件

#include <stdio.h>#include <stdlib.h>#include <time.h>

2、定义栈

typedef struct Stack {    int *data;    int top, size;} Stack;

3、初始化栈

Stack *init(int n) {    Stack *s = (Stack *)malloc(sizeof(Stack));    s->data = (int *)malloc(sizeof(int) * n);    s->size = n;    s->top = -1;    return s;}

4、判断是否为空及查看栈顶

int empty(Stack *s) {    return s->top == -1;}int top(Stack *s) {    if (empty(s)) return 0;    return s->data[s->top];}

5、插入

int push(Stack *s, int val) {    if (s == NULL) return 0;    if (s->top + 1 == s->size) return 0;    s->top += 1;    s->data[s->top] = val;    return 1;}

6、出栈操作

int pop(Stack *s) {    if (s == NULL) return 0;    if (empty(s)) return 0;    s->top -= 1;    return 1;}

7、清空

void clear(Stack *s) {    if (s == NULL) return ;    free(s->data);    free(s);    return ;}

8、输出栈

void output(Stack *s) {    printf("stack(%d) = [", s->top + 1);    for (int i = s->top; i >= 0; i--) {        printf(" %d", s->data[i]);    }    printf("]
");    return ;}

9、主函数（随机进行20次随机测试）

int main() {    srand(time(0));    #define MAX_OP 20    Stack *s = init(MAX_OP);    for (int i = 0; i < MAX_OP; i++) {        int op = rand() % 2, val = rand() % 100;        switch (op) {            case 0: {                printf("push %d to stack = %d
", val, push(s, val));            } break;            case 1: {                printf("pop %d from stack = %d
", top(s), pop(s));            }        }        output(s);    }    return 0;}

10、完整代码

 #include <stdio.h>#include <stdlib.h>#include <time.h>typedef struct Stack {    int *data;    int top, size;} Stack;Stack *init(int n) {    Stack *s = (Stack *)malloc(sizeof(Stack));    s->data = (int *)malloc(sizeof(int) * n);    s->size = n;    s->top = -1;    return s;}int empty(Stack *s) {    return s->top == -1;}int top(Stack *s) {    if (empty(s)) return 0;    return s->data[s->top];}int push(Stack *s, int val) {    if (s == NULL) return 0;    if (s->top + 1 == s->size) return 0;    s->top += 1;    s->data[s->top] = val;     西藏干部培训学校 www.swuplganxun.com return 1;}int pop(Stack *s) {    if (s == NULL) return 0;    if (empty(s)) return 0;    s->top -= 1;    return 1;}void clear(Stack *s) {    if (s == NULL) return ;    free(s->data);    free(s);    return ;}void output(Stack *s) {    printf("stack(%d) = [", s->top + 1);    for (int i = s->top; i >= 0; i--) {        printf(" %d", s->data[i]);    }    printf("]
");    return ;}int main() {    srand(time(0));    #define MAX_OP 20    Stack *s = init(MAX_OP);    for (int i = 0; i < MAX_OP; i++) {        int op = rand() % 2, val = rand() % 100;        switch (op) {            case 0: {                printf("push %d to stack = %d
", val, push(s, val));            } break;            case 1: {                printf("pop %d from stack = %d
", top(s), pop(s));            }        }        output(s);    }    return 0;}

 

三、栈的基本概念

要搞清楚这个概念，首先要明白”栈“原来的意思，如此才能把握本质。栈,存储货物或供旅客住宿的地方,可引申为仓库、中转站，所以引入到计算机领域里，就是指数据暂时存储的地方，所以才有进栈、出栈的说法。