C語言字符串中的括號匹配檢查

在C語言中，我們可以使用棧數據結構來實現括號匹配檢查

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

typedef struct Stack {
    char *data;
    int top;
    int size;
} Stack;

Stack *createStack(int size) {
    Stack *stack = (Stack *)malloc(sizeof(Stack));
    stack->data = (char *)malloc(size * sizeof(char));
    stack->top = -1;
    stack->size = size;
    return stack;
}

void push(Stack *stack, char value) {
    if (stack->top == stack->size - 1) {
        printf("Stack is full\n");
        return;
    }
    stack->data[++stack->top] = value;
}

char pop(Stack *stack) {
    if (stack->top == -1) {
        printf("Stack is empty\n");
        return '\0';
    }
    return stack->data[stack->top--];
}

int isEmpty(Stack *stack) {
    return stack->top == -1;
}

int isMatchingPair(char opening, char closing) {
    if (opening == '(' && closing == ')') return 1;
    if (opening == '{' && closing == '}') return 1;
    if (opening == '[' && closing == ']') return 1;
    return 0;
}

int areBracketsBalanced(char *expression) {
    int length = strlen(expression);
    Stack *stack = createStack(length);

    for (int i = 0; i< length; i++) {
        if (expression[i] == '(' || expression[i] == '{' || expression[i] == '[') {
            push(stack, expression[i]);
        } else if (expression[i] == ')' || expression[i] == '}' || expression[i] == ']') {
            if (isEmpty(stack)) {
                return 0;
            } else {
                char openingBracket = pop(stack);
                if (!isMatchingPair(openingBracket, expression[i])) {
                    return 0;
                }
            }
        }
    }

    return isEmpty(stack);
}

int main() {
    char expression[] = "({[]})";
    if (areBracketsBalanced(expression)) {
        printf("The brackets are balanced\n");
    } else {
        printf("The brackets are not balanced\n");
    }
    return 0;
}

這個程序首先定義了一個棧結構，然后實現了創建棧、入棧、出棧等基本操作。接下來，我們定義了一個isMatchingPair函數，用于判斷兩個括號是否匹配。areBracketsBalanced函數遍歷輸入的字符串，遇到開括號就入棧，遇到閉括號就出棧并檢查是否匹配。最后，如果棧為空，說明括號匹配成功，否則失敗。

在main函數中，我們測試了一個包含圓括號、花括號和方括號的字符串，如果括號匹配，輸出"The brackets are balanced"，否則輸出"The brackets are not balanced"。