C语言代码，用顺序栈检查输入括号序列的匹配情况

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

#define STACK_INIT_SIZE 20  //栈的初始长度
#define STACK_INCREMENT 10  //栈的增量

typedef char ElemType;

typedef struct {
    ElemType *base;  //指向栈底的指针
    ElemType *top;   //指向栈顶的指针
    int stacksize;    //当前已分配的存储空间，以元素为单位
}SqStack;

//初始化栈
void InitStack(SqStack *S) {
    S->base = (ElemType*)malloc(STACK_INIT_SIZE * sizeof(ElemType));
    if (!S->base) {
        exit(0);
    }
    S->top = S->base;
    S->stacksize = STACK_INIT_SIZE;
}

//销毁栈
void DestroyStack(SqStack *S) {
    free(S->base);
    S->stacksize = 0;
    S->top = S->base = NULL;
}

//判断栈是否为空
int StackEmpty(SqStack S) {
    if (S.top == S.base) {
        return 1;
    }
    return 0;
}

//获取栈中元素个数
int StackLength(SqStack S) {
    return (S.top - S.base);
}

//获取栈顶元素
ElemType GetTop(SqStack S) {
    if (S.top != S.base) {
        return *(S.top - 1);
    }
    return ' ';
}

//入栈
void Push(SqStack *S, ElemType e) {
    if (S->top - S->base >= S->stacksize) {
        S->base = (ElemType*)realloc(S->base, (S->stacksize + STACK_INCREMENT) * sizeof(ElemType));
        if (!S->base) {
            exit(0);
        }
        S->top = S->base + S->stacksize;
        S->stacksize += STACK_INCREMENT;
    }
    *(S->top) = e;
    S->top++;
}

//出栈
void Pop(SqStack *S, ElemType *e) {
    if (S->top == S->base) {
        exit(0);
    }
    S->top--;
    *e = *(S->top);
}

//检查输入括号序列的匹配情况
void Match(SqStack *S) {
    char c;
    while ((c = getchar()) != EOF) {
        switch (c) {
        case '(':
            Push(S, c);
            break;
        case ')':
            if (GetTop(*S) == '(') {
                Pop(S, &c);
            } else {
                printf("Right brackets are missing!\n");
                DestroyStack(S);
                return;
            }
            break;
        case '[':
            Push(S, c);
            break;
        case ']':
            if (GetTop(*S) == '[') {
                Pop(S, &c);
            } else {
                printf("Right brackets are missing!\n");
                DestroyStack(S);
                return;
            }
            break;
        case '{':
            Push(S, c);
            break;
        case '}':
            if (GetTop(*S) == '{') {
                Pop(S, &c);
            } else {
                printf("Right brackets are missing!\n");
                DestroyStack(S);
                return;
            }
            break;
        default:
            break;
        }
    }
    if (StackEmpty(*S)) {
        printf("The brackets are matched!\n");
    } else {
        printf("Left brackets are missing!\n");
    }
    DestroyStack(S);
}

int main() {
    SqStack S;
    InitStack(&S);
    printf("Please input bracket sequence:\n");
    Match(&S);
    return 0;
}