栈

栈是只允许在一端进行插入或删除操作的线性表。

顺序存储实现栈

#include <stdio.h>#define MAXSIZE 50
typedef int ElemType;typedef struct {// 数组ElemType data[MAXSIZE];// 始终指向栈顶int top;
} SqStack;/** 初始化栈*/
void init_stack(SqStack &S) {// top等于-1时表示栈为空S.top = -1;
}/** 判断栈是否为空*/
bool stack_empty(SqStack S) {if (-1 == S.top) {return true;} else {return false;}
}/** 入栈*/
bool push(SqStack &S, ElemType data) {// 判断是否栈满if (MAXSIZE - 1 == S.top) {return false;}// S.top = S.top + 1// S.data[S.top] = dataS.data[++S.top] = data;return true;
}/** 获取栈顶元素*/
bool get_top(SqStack S, ElemType &elem) {// 判断栈是否为空if (stack_empty(S)) {return false;}elem = S.data[S.top];return true;
}/** 出栈*/
bool pop(SqStack &S, ElemType &elem) {// 判断栈是否为空if (stack_empty(S)) {return false;}// elem = S.data[S.top]// S.top = S.top - 1elem = S.data[S.top--];return true;
}int main() {// 一、定义一个栈SqStack S;// 二、初始化栈init_stack(S);// 三、判断是否为空bool flag = stack_empty(S);if (flag) {printf("stack is empty!\n");}// 四、入栈push(S, 3);push(S, 4);push(S, 5);// 五、获取栈顶元素ElemType elem;flag = get_top(S, elem);if (flag) {printf("get top: %d\n", elem);}// 六、出栈flag = pop(S, elem);if (flag) {printf("pop element: %d\n", elem);}return 0;
}

链式存储实现栈

链表头插法实现入栈，链表头删法实现出栈。

#include <stdio.h>
#include <stdlib.h>typedef int ElemType;
typedef struct LStack {ElemType data;struct LStack *next;
} LStack, *LinkStack;int main() {// 栈LinkStack S = (LinkStack) malloc(sizeof(LStack));S->next = NULL;// 栈顶LinkStack top = (LinkStack) malloc(sizeof(LStack));top->next = NULL;// 入栈 链表头插法top->data = 1;top->next = S->next;S->next = top;// 出栈 链表头删法ElemType c = top->data;S->next = top->next;free(top);top = S->next;// 判断栈空栈满if (NULL == S->next) {printf("stack is empty\n");}// 只要内存足够 栈可以继续添加元素return 0;
}