栈应用 - 括号匹配问题

针对第3个应用写个代码

import org.junit.Test;

/**
 * 功能说明:括号合法检测
 * 1, 使用栈结构压栈左括号;
 * 2, 遇到右括号, 弹栈, 与该栈顶元素匹配, 如果配对则继续
 * 3, 如果遇到不匹配的括号对, 则匹配失败
 * <p>
 * 使用ArrayStackPlus实现该程序
 * 开发人员:@author MaLi
 */
public class BracketsMatching {
    
    
    /**
     * 检测入口
     *
     * @param brackets 含有括号的字符串
     * @return true即括号匹配合法
     */
    public boolean match(String brackets) {
    
    
        int length = brackets.length();
        ArrayStack stack = new ArrayStack(length);
        boolean result = false;
        for (int i = 0; i < length; i++) {
    
    
            result = controller(stack, brackets.charAt(i));
            if (!result) {
    
    
                System.out.println("不匹配的括号");
                return false;
            }
        }
        System.out.println("合法的括号");
        return true;
    }

    /**
     * 决定入栈or匹配
     * 是左括号 - 入栈
     * 是右括号 - 与栈顶元素匹配
     *
     * @param stack   栈结构
     * @param bracket 字符串的字符
     * @return 左右两边匹配成功返回true
     */
    public boolean controller(ArrayStack stack, char bracket) {
    
    
        boolean flag = false;
        switch (bracket) {
    
    
            //1, 遇到左, 入栈
            case '{':
            case '[':
            case '(':
                stack.push(bracket);
                flag = true;
                break;
            //2, 遇到右, 弹栈并比较
            case '}':
            case ']':
            case ')':
                Character left = (Character) stack.pop();
                flag = check(left, bracket);
                break;
            default:
                flag = true;
                break;
        }
        return flag;
    }

    /**
     * 左右两边括号匹配比较
     *
     * @param left  左括号
     * @param right 右括号
     * @return 匹配返回true
     */
    public boolean check(char left, char right) {
    
    
        boolean result = false;
        if ((left == '{' && right == '}') || (left == '[' && right == ']') || (left == '(' && right == ')')) {
    
    
            result = true;
        }
        return result;
    }


    @Test
    public void testMatch() {
    
    
        String brackets = "{[(())]}";
        match(brackets);
    }
}

固定长度的栈

/**
 * 功能说明:实现顺序栈
 * 时间复杂度: O(1)
 * 空间复杂度: O(1)
 * 开发人员:@author MaLi
 */
public class ArrayStack<T> {
    
    
    private Object[] container;
    private int length;
    private int index;

    public ArrayStack(int length) {
    
    
        this.length = length;
        this.index = 0;
        this.container = new Object[length];
    }

    public boolean push(T t) {
    
    
        boolean isSuccess = false;
        if (this.index < length) {
    
    
            container[index++] = t;
            isSuccess = true;
        }
        return isSuccess;
    }

    public T pop() {
    
    
        T t = null;
        if (this.index > 0) {
    
    
            t = (T) container[--index];
        }
        return t;
    }
}

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转载自blog.csdn.net/malipku/article/details/121133344