【LeetCode】Easy | 20. Valid parentheses

subject ：

Ideas ：

Pictured

Code ：

typedef char STDataType;
typedef struct Stack
{
    
	STDataType* a;
	int top;
	int capacity;
}ST;
// initialization 
void StackInit(ST* ps)
{
    
	assert(ps);
	ps->a = NULL;
	ps->top = 0;
	ps->capacity = 0;
}
// Push 
void StackPush(ST* ps, STDataType x)
{
    
	assert(ps);
	// Judge whether there is enough space 
	// The space is insufficient 
	if (ps->top == ps->capacity)
	{
    
		int newCapacity = (ps->capacity == 0) ? 4 : ps->capacity * 2;
		STDataType* tmp = realloc(ps->a, sizeof(STDataType) * newCapacity);
		// Failed to open up 
		if (tmp == NULL)
		{
    
			printf("realloc fail!");
			exit(0);
		}
		// It's a success 
		ps->a = tmp;
		ps->capacity = newCapacity;
	}
	ps->a[ps->top] = x;
	ps->top++;
}
// Out of the stack 
void StackPop(ST* ps)
{
    
	assert(ps);
	assert(ps->top > 0);
	ps->top--;
}
// Take the top element of the stack 
STDataType StackTop(ST* ps)
{
    
	assert(ps);
	assert(ps->top > 0);
	return ps->a[ps->top - 1];
}

// Judge whether the stack is empty 
bool StackEmpty(ST* ps)
{
    
	assert(ps);
	return ps->top == 0;
}
// Destruction of the stack 
void StackDestroy(ST* ps)
{
    
	assert(ps);
	free(ps->a);
	ps->a = NULL;
	ps->top = ps->capacity = 0;
}
bool isValid(char * s){
    
    ST st;
    StackInit(&st);
    while(*s)
    {
    
        if(*s=='{'|| *s=='[' || *s=='(')
        {
    
            StackPush(&st,*s);
            s++;
        }
        else
        {
    
            if(StackEmpty(&st))
            {
    
                StackDestroy(&st);
                return false;
            }
            char topElem=StackTop(&st);
            StackPop(&st);
            if((topElem == '('&&*s != ')')
            ||(topElem == '{'&&*s != '}')
            ||(topElem == '['&&*s != ']')
            )
            {
    
                StackDestroy(&st);
                return false;
            }
            else{
    
                s++;
            }
        }
    }
    if(StackEmpty(&st))
    {
    
        return true;
    }
    return false;
}