用户输入括号是否匹配

约定不等于承诺〃 2023-10-05 22:22 28阅读 0赞

public class brackets {
        /*算法*/
        public static boolean isMatch(String str) {        
            int i = 0;
            char e, x;
            SqStackClass<Character> st = new SqStackClass<Character>();    //建立一个顺序栈
    
            while (i < str.length()) {
                e = str.charAt(i);
                if (e == '(' || e == '[' || e == '{') {
                    st.push(e);                             //将左括号进栈
                } else {
                    if (e == ')') {
                        if (st.empty()) {
                            return false;        //栈空返回false
                        }
                        if (st.peek() != '(') {
                            return false;    //栈顶不是匹配的'('返回false
                        }
                        st.pop();
                    }
                    if (e == ']') {
                        if (st.empty()) {
                            return false;               //栈空返回false
                        }
                        if (st.peek() != '[') {
                            return false;//栈顶不是匹配的'['返回false
                        }
                        st.pop();
                    }
                    if (e == '}') {
                        if (st.empty()) {
                            return false;//栈空返回false
                        }
                        if (st.peek() != '{') {
                            return false;//栈顶不是匹配的'{'返回false
                        }
                        st.pop();
                    }
                }
                i++;                                        //继续遍历str
            }
            if (st.empty()) {
                return true;//栈空返回true
            }
            else {
                return false;//栈不空返回false
            }
        }
    
        public static void main(String[] args) {
            System.out.println("-------测试1----------");
            String str = "([)]";
            if (isMatch(str))
                System.out.println(str + "中括号是匹配的");
            else
                System.out.println(str + "中括号不匹配");
    
            System.out.println("-----------测试2------------");
            str = "([])";
            if (isMatch(str))
                System.out.println(str + "中括号是匹配的");
            else
                System.out.println(str + "中括号不匹配");
    
        }