#20 Valid Parentheses

Title Link: https://leetcode.com/problems/valid-parentheses/

Given A string containing just the characters‘(‘,‘)‘,‘{‘,‘}‘,‘[‘and‘]‘, determine if the input string is valid.

the brackets must close in the correct order, " () "  and " () []{} "  are all valid But " (] "  and " ([)] "  are not.

typedef struct STACKRECORD {    //Do not consider overflow stack implementation simple stack char ch[100];int top;} *stack;bool isEmpty (Stack stack) {if (stack->top >= 0) return False;return true;} Stack init () {Stack stack = (stack) malloc (sizeof (struct stackrecord)); stack->top = -1;return stack;} void push (char ch, stack stack) {stack->ch[++stack->top] = ch;} Char top (Stack stack) {     //returns the top element of the stack, returning '!isempty '    if (stack) return stack->ch[stack->top]; when empty stack    return 0;} void pop (stack stack) {--stack->top;} BOOL IsValid (char* s) {Stack stack = init (); while (*s) {switch (*s) {case ' (':       ///left parenthesis into stack case ' [': Case ' {':p ush (*s, Stack Break;case ') ':      //Right parenthesis to see if the top of the stack is a corresponding opening parenthesis. Does not return false, otherwise out of stack if (Top (stack)! = ' (') return False;pop (stack); Break;case ': if (stack) = ' [') Return False;pop (stack ); Break;case '} ': if (top (stack) = ' {') return False;pop (stack); Break;default:return false;} ++s;} if (!isempty (stack))        //stack is not empty description has extra opening parenthesis return False;return true;}

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#20 Valid Parentheses