堆栈--括号匹配检验

根据堆栈LIFO原理，对括号的匹配进行检验：

#include<stdio.h>#include<stdlib.h>#define STACK_SIZE     1024#define TYPE           chartypedef struct {TYPE *base;TYPE *top;int stack_size;}STACK;int stack_init(STACK *s){s->base = malloc(STACK_SIZE * sizeof(TYPE));if (s->base == NULL){return -1;}s->top = s->base;s->stack_size = STACK_SIZE;return 0;}void stack_destroy(STACK *s){free(s->base);s->base = s->top = NULL;s->stack_size = 0;}void stack_clear(STACK *s){s->top = s->base;}int stack_length(STACK *s){return (s->top - s->base);}int stack_empty(STACK *s){return (s->top == s->base);}TYPE stack_top(STACK *s, TYPE *e){if (stack_length(s) == 0){return -1;}*e = *(s->top - 1);return *e;}int stack_push(STACK *s, TYPE e){if (stack_length(s) >= s->stack_size){return -1;}*(s->top++) = e;return 0;}int stack_pop(STACK *s, TYPE *e){if (stack_length(s) == 0){return -1;}*e = *(--s->top);return 0;}int main(){STACK *s;char symbol, elem;FILE *fd;fd = fopen("symbol", "r");if (fd == NULL){return -1;}s = (STACK *)malloc(sizeof(STACK));if (s == NULL){return -1;}stack_init(s);while(fread(&symbol, sizeof(symbol), 1, fd) == 1){if (stack_empty(s)){if (symbol == '('|| symbol == '['|| symbol == '{'){stack_push(s, symbol);}}else{if ((symbol - stack_top(s, &elem) == 1) || (symbol - stack_top(s, &elem) == 2)|| (symbol - stack_top(s, &elem) == 2)){stack_pop(s, &symbol);}else{if (symbol == '('|| symbol == '{'|| symbol == '['){stack_push(s, symbol);}}}}if (stack_empty(s)){printf("correct symbol\n");}else{printf("wrong symbol\n");}return 0;}