typedef char STDataType;
//动态栈
#define allocator_may_return_null 1typedef struct ST {STDataType* _a;int _top;//栈顶元素int _capacity;//最大容量
}Stack;
//初始化栈
void StackInit(Stack *pst);//入栈
void StackPush(Stack* pst, STDataType x);//出栈
void StackPop(Stack* pst);//获取栈顶元素
STDataType StackTop(Stack* pst);//判断栈是否为空，是返回1，非空返回0
bool StackEmpty(Stack* pst);//打印栈
void StackPrint(Stack* pst);//销毁栈
void StackDestory(Stack* pst);//初始化栈
void StackInit(Stack* pst)
{assert(pst);pst->_a = NULL;pst->_top = 0;pst->_capacity = 0;
}
//入栈
void StackPush(Stack* pst, STDataType x)
{assert(pst);if (pst->_top == pst->_capacity){int newcapacity = pst->_capacity == 0 ? 4 : (pst->_capacity * 2);STDataType* temp = (STDataType*)realloc(pst->_a, sizeof(STDataType) * newcapacity);if (temp == NULL){printf("realloc fail\n");exit(1);}pst->_a = temp;pst->_capacity = newcapacity;}pst->_a[pst->_top] = x;pst->_top++;
}//出栈
void StackPop(Stack* pst)
{assert(pst);assert(pst->_top > 0);pst->_top--;
}//获取栈顶元素
STDataType StackTop(Stack* pst)
{assert(pst);assert(pst->_top>0);return pst->_a[pst->_top-1];
}//获取栈的有效元素个数
int StackSize(Stack* pst)
{assert(pst);return pst->_top;
}//判断栈是否为空，是返回1，非空返回0
bool StackEmpty(Stack* pst)
{assert(pst);if (pst->_top == 0)return true;elsereturn false;
}//打印栈
void StackPrint(Stack* pst)
{while (!StackEmpty(pst)){printf("%d\n", StackTop(pst));StackPop(pst);}
}//销毁栈
void StackDestory(Stack* pst)
{assert(pst);free(pst->_a);pst->_a = NULL;pst->_top = pst->_capacity = 0;
}
#include "string.h"
bool isValid(char* s) {Stack st;StackInit(&st);int n=strlen(s);if(n%2!=0)return false;for(int i=0;i<n;i++,s++){switch(*s){case '(':{StackPush(&st,*s);}break;case '[':{StackPush(&st,*s);}break;case '{':{StackPush(&st,*s);}break;case ')':{if(st._top==0)return false;char m=StackTop(&st);StackPop(&st);if(m!='('){return false;}}break;case '}':{if(st._top==0)return false;char m=StackTop(&st);StackPop(&st);if(m!='{'){return false;}}break;case ']':{if(st._top==0)return false;char m=StackTop(&st);StackPop(&st);if(m!='['){return false;}}break;}}if(st._top>0){return false;}if(StackEmpty(&st)&&*s!='\0')return false;
StackDestory(&st);return true;
}