括号匹配算法java实现

括号匹配算法：

package com.jintao.example.algorithm;

import java.util.HashMap;
import java.util.Map;
import java.util.Stack;

/**
 * @author jinjueYang
 * @description 括号匹配
 * @date 2019/11/2 9:02
 */
public class BracketsMatch {

    private static final Map<Character, Character> bracketsMap = new HashMap();

    static {
        bracketsMap.put(')', '(');
        bracketsMap.put('}', '{');
        bracketsMap.put(']', '[');
        bracketsMap.put('>', '<');
    }

    public static void main(String[] args) {
        System.out.println(isMatch("(32+9)*5+[9-9{]}"));
        System.out.println(isMatch("(32+9)*5+[9-9{}]"));
        System.out.println(isMatch("<Y>{F}"));
        System.out.println(isMatch("<Y>{F}[{]"));
    }

    public static boolean isMatch(String str) {
        if (null == str) {
            return false;
        }
        char[] ch = str.toCharArray();
        Stack<Character> stack = new Stack<>();
        for (char c : ch) {
            if (bracketsMap.containsValue(c)) {
                //遇到左括号入栈
                stack.push(c);
            } else if (bracketsMap.containsKey(c)) {
                //遇到右括号出栈，如果栈为空或出栈的括号不匹配那么表示匹配失败
                if (stack.empty() || (!stack.pop().equals(bracketsMap.get(c)))) {
                    return false;
                }
            }
        }
        return stack.isEmpty();
    }
}

运行结果：

false
true
true
false