純C語言實現鏈棧

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

typedef int ElemType;

typedef struct StackNode{
    ElemType data;
    struct StackNode *next;
}StackNode;

StackNode *InitStack(StackNode *S);//初始化
StackNode * DestroyStack(StackNode*S);//銷燬
void ClearStack(StackNode*S);//清空
int StackEmpty(StackNode*S);//判空
int StackLength(StackNode*S);//棧長度
ElemType GetTop(StackNode*S);//獲取棧頂元素，不修改指針位置
StackNode *Push(StackNode*S, ElemType e);//插入棧頂
StackNode *Pop(StackNode *S, ElemType *e);//刪除棧頂
void StackTraverse(StackNode *S);//從棧頂依次遍歷

//初始化
StackNode *InitStack(StackNode *S){
    S = NULL;
    printf("初始化成功\n");
    return S;
}

//銷燬,返回空指針給S
StackNode *DestroyStack(StackNode*S){
    StackNode *p = S->next;
    while(p){
        free(S);
        S = p;
        p = p->next;
    }
    printf("銷燬成功\n");
    return NULL;
}

//清空
void ClearStack(StackNode*S){
    printf("清空\n");
    StackNode *p = S;
    while(p!=NULL){
        p->data = 0;
        p = p->next;
    }
    printf("清空成功\n");
}

//判空
int StackEmpty(StackNode*S);

//棧長度
int StackLength(StackNode*S){
    int len = 0;
    StackNode *p = S;
    while(p!=NULL){
        len++;
        p = p->next;
    }
    return len;
}

//獲取棧頂元素，不修改指針位置
ElemType GetTop(StackNode*S){
    if(S!=NULL){
        printf("棧頂元素爲%d", S->data);
        return S->data;
    }else{
        printf("空鏈棧無棧頂元素\n");
        return NULL;
    }
}

//插入棧頂,返回指針指向當前棧頂
StackNode *Push(StackNode*S, ElemType e){
    StackNode *p = NULL;
    p = (StackNode *)malloc(sizeof(StackNode));
    p->data = e;
    p->next = S;
    S = p;
    printf("%d入棧成功\n", e);
    return S;
}

//刪除棧頂,返回指針指向當前棧頂
StackNode *Pop(StackNode *S, ElemType *e){
    StackNode *p = NULL;//用於暫存刪除元素
    if(S == NULL){
        printf("空鏈棧，刪除失敗\n");
        return NULL;
    }
    *e = S->data;
    p = S;
    S = S->next;
    free(p);
    printf("%d出棧成功\n",*e);
    return S;
}

//從棧頂依次遍歷
void StackTraverse(StackNode *S){
    StackNode *p = S;
    if(p == NULL){
        printf("空鏈棧\n");
        return;
    }
    while(p != NULL){
        printf("%d ", p->data);
        p = p->next;
    }
    printf("\n");
}



int main(void){
    StackNode *S;
    ElemType e;
    //初始化測試
    S = InitStack(S);

//    //獲取棧頂元素測試
//    GetTop(S);
//    S = Push(S, 999);
//    GetTop(S);

    //入棧測試
    S = Push(S, 1);
    S = Push(S, 3);
    S = Push(S, 2);
    S = Push(S, 4);
    S = Push(S, 7);

    //棧長測試
    printf("棧長%d\n",StackLength(S));

    //遍歷測試
    StackTraverse(S);

//    //出棧測試
//    S = Pop(S, &e);
//    S = Pop(S, &e);
//    S = Pop(S, &e);
//    //printf("測試e是否改變: %d\n",e);
//    S = Pop(S, &e);
//    StackTraverse(S);

//    //清空測試
//    ClearStack(S);
//    StackTraverse(S);

////    //銷燬測試
//    S = DestroyStack(S);
//    StackTraverse(S);

    return 0;
}