ter = array_value($config, 'filter'); $arr = array_value($filter, $type); $enable = array_value($arr, 'enable'); $wordarr = array_value($arr, 'keyword'); if (0 == $enable || empty($wordarr)) return FALSE; foreach ($wordarr as $_keyword) { if (!$_keyword) continue; $r = strpos(strtolower($keyword), strtolower($_keyword)); if (FALSE !== $r) { $error = $_keyword; return TRUE; } } return FALSE; } // return http://domain.com OR https://domain.com function url_prefix() { $http = ((isset($_SERVER['HTTPS']) && 'on' == $_SERVER['HTTPS']) || (isset($_SERVER['HTTP_X_FORWARDED_PROTO']) && $_SERVER['HTTP_X_FORWARDED_PROTO'] == 'https')) ? 'https://' : 'http://'; return $http . $_SERVER['HTTP_HOST']; } // 唯一身份ID function uniq_id() { return uniqid(substr(md5(microtime(true) . mt_rand(1000, 9999)), 8, 8)); } // 生成订单号 14位 function trade_no() { $trade_no = str_replace('.', '', microtime(1)); $strlen = mb_strlen($trade_no, 'UTF-8'); $strlen = 14 - $strlen; $str = ''; if ($strlen) { for ($i = 0; $i <= $strlen; $i++) { if ($i < $strlen) $str .= '0'; } } return $trade_no . $str; } // 生成订单号 16位 function trade_no_16() { $explode = explode(' ', microtime()); $trade_no = $explode[1] . mb_substr($explode[0], 2, 6, 'UTF-8'); return $trade_no; } // 当前年的天数 function date_year($time = NULL) { $time = intval($time) ? $time : time(); return date('L', $time) + 365; } // 当前年份中的第几天 function date_z($time = NULL) { $time = intval($time) ? $time : time(); return date('z', $time); } // 当前月份中的第几天，没有前导零 1 到 31 function date_j($time = NULL) { $time = intval($time) ? $time : time(); return date('j', $time); } // 当前月份中的第几天，有前导零的2位数字 01 到 31 function date_d($time = NULL) { $time = intval($time) ? $time : time(); return date('d', $time); } // 当前时间为星期中的第几天 数字表示 1表示星期一 到 7表示星期天 function date_w_n($time = NULL) { $time = intval($time) ? $time : time(); return date('N', $time); } // 当前日第几周 function date_d_w($time = NULL) { $time = intval($time) ? $time : time(); return date('W', $time); } // 当前几月 没有前导零1-12 function date_n($time = NULL) { $time = intval($time) ? $time : time(); return date('n', $time); } // 当前月的天数 function date_t($time = NULL) { $time = intval($time) ? $time : time(); return date('t', $time); } // 0 o'clock on the day function clock_zero() { return strtotime(date('Ymd')); } // 24 o'clock on the day function clock_twenty_four() { return strtotime(date('Ymd')) + 86400; } // 8点过期 / expired at 8 a.m. function eight_expired($time = NULL) { $time = intval($time) ? $time : time(); // 当前时间大于8点则改为第二天8点过期 $life = date('G') <= 8 ? (strtotime(date('Ymd')) + 28800 - $time) : clock_twenty_four() - $time + 28800; return $life; } // 24点过期 / expired at 24 a.m. function twenty_four_expired($time = NULL) { $time = intval($time) ? $time : time(); $twenty_four = clock_twenty_four(); $life = $twenty_four - $time; return $life; } /** * @param $url 提交地址 * @param string $post POST数组 / 空为GET获取数据 / $post='GET'获取连续跳转最终URL * @param string $cookie cookie * @param int $timeout 超时 * @param int $ms 设为1是毫秒 * @return mixed 返回数据 */ function https_request($url, $post = '', $cookie = '', $timeout = 30, $ms = 0) { if (empty($url)) return FALSE; if (version_compare(PHP_VERSION, '5.2.3', '<')) { $ms = 0; $timeout = 30; } is_array($post) and $post = http_build_query($post); // 没有安装curl 使用http的形式，支持post if (!extension_loaded('curl')) { //throw new Exception('server not install CURL'); if ($post) { return https_post($url, $post, $cookie, $timeout); } else { return http_get($url, $cookie, $timeout); } } is_array($cookie) and $cookie = http_build_query($cookie); $curl = curl_init(); // 返回执行结果，不输出 curl_setopt($curl, CURLOPT_RETURNTRANSFER, true); //php5.5跟php5.6中的CURLOPT_SAFE_UPLOAD的默认值不同 if (class_exists('\CURLFile')) { curl_setopt($curl, CURLOPT_SAFE_UPLOAD, true); } else { defined('CURLOPT_SAFE_UPLOAD') and curl_setopt($curl, CURLOPT_SAFE_UPLOAD, false); } // 设定请求的RUL curl_setopt($curl, CURLOPT_URL, $url); // 设定返回信息中包含响应信息头 if (ini_get('safe_mode') && ini_get('open_basedir')) { // $post参数必须为GET if ('GET' == $post) { // 安全模式时将头文件的信息作为数据流输出 curl_setopt($curl, CURLOPT_HEADER, true); // 安全模式采用连续抓取 curl_setopt($curl, CURLOPT_NOBODY, true); } } else { curl_setopt($curl, CURLOPT_HEADER, false); // 允许跳转10次 curl_setopt($curl, CURLOPT_MAXREDIRS, 10); // 使用自动跳转，返回最后的Location curl_setopt($curl, CURLOPT_FOLLOWLOCATION, true); } $ua1 = 'Mozilla/5.0 (iPhone; CPU iPhone OS 13_2_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.0.3 Mobile/15E148 Safari/604.1'; $ua = empty($_SERVER["HTTP_USER_AGENT"]) ? $ua1 : $_SERVER["HTTP_USER_AGENT"]; curl_setopt($curl, CURLOPT_USERAGENT, $ua); // 兼容HTTPS if (FALSE !== stripos($url, 'https://')) { curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, FALSE); curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, FALSE); //ssl版本控制 //curl_setopt($curl, CURLOPT_SSLVERSION, CURL_SSLVERSION_TLSv1); curl_setopt($curl, CURLOPT_SSLVERSION, true); } $header = array('Content-type: application/x-www-form-urlencoded;charset=UTF-8', 'X-Requested-With: XMLHttpRequest'); $cookie and $header[] = "Cookie: $cookie"; curl_setopt($curl, CURLOPT_HTTPHEADER, $header); if ($post) { // POST curl_setopt($curl, CURLOPT_POST, true); // 自动设置Referer curl_setopt($curl, CURLOPT_AUTOREFERER, true); curl_setopt($curl, CURLOPT_POSTFIELDS, $post); } if ($ms) { curl_setopt($curl, CURLOPT_NOSIGNAL, true); // 设置毫秒超时 curl_setopt($curl, CURLOPT_TIMEOUT_MS, intval($timeout)); // 超时毫秒 } else { curl_setopt($curl, CURLOPT_TIMEOUT, intval($timeout)); // 秒超时 } //优先解析 IPv6 超时后IPv4 //curl_setopt($curl, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V4); curl_setopt($curl, CURLOPT_ENCODING, 'gzip'); // 返回执行结果 $output = curl_exec($curl); // 有效URL，输出URL非URL页面内容 CURLOPT_RETURNTRANSFER 必须为false 'GET' == $post and $output = curl_getinfo($curl, CURLINFO_EFFECTIVE_URL); curl_close($curl); return $output; } function save_image($img) { $ch = curl_init(); // 设定请求的RUL curl_setopt($ch, CURLOPT_URL, $img); // 设定返回信息中包含响应信息头 启用时会将头文件的信息作为数据流输出 //curl_setopt($ch, CURLOPT_HEADER, false); //curl_setopt($ch, CURLOPT_USERAGENT, $_SERVER["HTTP_USER_AGENT"]); // true表示$html,false表示echo $html curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 10); curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false); curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); //curl_setopt($ch, CURLOPT_BINARYTRANSFER, 1); //curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 0); curl_setopt($ch, CURLOPT_ENCODING, 'gzip'); $output = curl_exec($ch); curl_close($ch); return $output; } // 计算字串宽度:剧中对齐(字体大小/字串内容/字体链接/背景宽度/倍数) function calculate_str_width($size, $str, $font, $width, $multiple = 2) { $box = imagettfbbox($size, 0, $font, $str); return ($width - $box[4] - $box[6]) / $multiple; } // 搜索目录下的文件 比对文件后缀 function search_directory($path) { if (is_dir($path)) { $paths = scandir($path); foreach ($paths as $val) { $sub_path = $path . '/' . $val; if ('.' == $val || '..' == $val) { continue; } else if (is_dir($sub_path)) { //echo '目录名:' . $val . '
'; search_directory($sub_path); } else { //echo ' 最底层文件: ' . $path . '/' . $val . '
'; $ext = strtolower(file_ext($sub_path)); if (in_array($ext, array('php', 'asp', 'jsp', 'cgi', 'exe', 'dll'), TRUE)) { echo '异常文件：' . $sub_path . '
'; } } } } } // 一维数组转字符串 $sign待签名字符串 $url为urlencode转码GET参数字符串 function array_to_string($arr, &$sign = '', &$url = '') { if (count($arr) != count($arr, 1)) throw new Exception('Does not support multi-dimensional array to string'); // 注销签名 unset($arr['sign']); // 排序 ksort($arr); reset($arr); // 转字符串做签名 $url = ''; $sign = ''; foreach ($arr as $key => $val) { if (empty($val) || is_array($val)) continue; $url .= $key . '=' . urlencode($val) . '&'; $sign .= $key . '=' . $val . '&'; } $url = substr($url, 0, -1); $url = htmlspecialchars($url); $sign = substr($sign, 0, -1); } // 私钥生成签名 function rsa_create_sign($data, $key, $sign_type = 'RSA') { if (!function_exists('openssl_sign')) throw new Exception('OpenSSL extension is not enabled'); if (!defined('OPENSSL_ALGO_SHA256')) throw new Exception('Only versions above PHP 5.4.8 support SHA256'); $key = wordwrap($key, 64, "\n", true); if (FALSE === $key) throw new Exception('Private Key Error'); $key = "-----BEGIN RSA PRIVATE KEY-----\n$key\n-----END RSA PRIVATE KEY-----"; if ('RSA2' == $sign_type) { openssl_sign($data, $sign, $key, OPENSSL_ALGO_SHA256); } else { openssl_sign($data, $sign, $key, OPENSSL_ALGO_SHA1); } // 加密 return base64_encode($sign); } // 公钥验证签名 function rsa_verify_sign($data, $sign, $key, $sign_type = 'RSA') { $key = wordwrap($key, 64, "\n", true); if (FALSE === $key) throw new Exception('Public Key Error'); $key = "-----BEGIN PUBLIC KEY-----\n$key\n-----END PUBLIC KEY-----"; // 签名正确返回1 签名不正确返回0 错误-1 if ('RSA2' == $sign_type) { $result = openssl_verify($data, base64_decode($sign), $key, OPENSSL_ALGO_SHA256); } else { $result = openssl_verify($data, base64_decode($sign), $key, OPENSSL_ALGO_SHA1); } return $result === 1; } // Array to xml array('appid' => 'appid', 'code' => 'success') function array_to_xml($arr) { if (!is_array($arr) || empty($arr)) throw new Exception('Array Error'); $xml = ""; foreach ($arr as $key => $val) { if (is_numeric($val)) { $xml .= "<" . $key . ">" . $val . ""; } else { $xml .= "<" . $key . ">"; } } $xml .= ""; return $xml; } // Xml to array function xml_to_array($xml) { if (!$xml) throw new Exception('XML error'); $old = libxml_disable_entity_loader(true); // xml解析 $result = (array)simplexml_load_string($xml, null, LIBXML_NOCDATA | LIBXML_COMPACT); // 恢复旧值 if (FALSE === $old) libxml_disable_entity_loader(false); return $result; } // 逐行读取 function well_import($file) { if ($handle = fopen($file, 'r')) { while (!feof($handle)) { yield trim(fgets($handle)); } fclose($handle); } } // 计算总行数 function well_import_total($file, $key = 'well_import_total') { static $cache = array(); if (isset($cache[$key])) return $cache[$key]; $count = cache_get($key); if (NULL === $count) { $count = 0; $globs = well_import($file); while ($globs->valid()) { ++$count; $globs->next(); // 指向下一个 } $count and cache_set($key, $count, 300); } return $cache[$key] = $count; } $g_dir_file = FALSE; function well_search_dir($path) { global $g_dir_file; FALSE === $g_dir_file and $g_dir_file = array(); if (is_dir($path)) { $paths = scandir($path); foreach ($paths as $val) { $sub_path = $path . '/' . $val; if ('.' == $val || '..' == $val) { continue; } else if (is_dir($sub_path)) { well_search_dir($sub_path); } else { $g_dir_file[] = $sub_path; } } } return $g_dir_file; } ?>java - Valid parenthesis problem passes tests but fails when I submit - Stack Overflow

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    java - Valid parenthesis problem passes tests but fails when I submit - Stack Overflow

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    I'm currently trying to solve the Valid Parenthesis problem on Leetcode, in Java, that goes as follows:

    Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.

    An input string is valid if:
    Open brackets must be closed by the same type of brackets.
    Open brackets must be closed in the correct order.
    Every close bracket has a corresponding open bracket of the same type"

    I followed the hints which told me to use a stack. Here is my code:

    import java.util.Stack;

class Solution {
    public boolean isValid(String s) {
        Stack<Character> values = new Stack<>();
        for (int i=0; i < s.length(); i++) {
            if (s.charAt(i) == '(' || s.charAt(i) == '[' || s.charAt(i) == '{') {
                values.push(s.charAt(i));
            }

            if ((s.charAt(i) == ')' && values.peek() == '(') || (s.charAt(i) == ']' && values.peek() == '[') || ((s.charAt(i) == '}') && values.peek() == '{')) {
                values.pop();
            }
        }
        if (values.empty()) {
            return true;
        } else {
            return false;
        }
    }
}

    This passes all the test cases, however when I press submit, it gives me the following error:

    java.util.EmptyStackException

    at line 103, java.base/java.util.Stack.peek
    at line 11, Solution.isValid
    at line 56, DriverSolution.helper
    at line 86, Driver.main

    After looking at the documentation for java.util.Stack, I've seen that under the method peek() it says:

    Throws:
    EmptyStackException - if this stack is empty.

    I understand it's to do with using peek() when the stack is empty, but I'm confused as to how to fix it since it somehow passed the tests before that. How do I fix this in my code?

    I'm currently trying to solve the Valid Parenthesis problem on Leetcode, in Java, that goes as follows:

    Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.

    An input string is valid if:
    Open brackets must be closed by the same type of brackets.
    Open brackets must be closed in the correct order.
    Every close bracket has a corresponding open bracket of the same type"

    I followed the hints which told me to use a stack. Here is my code:

    import java.util.Stack;

class Solution {
    public boolean isValid(String s) {
        Stack<Character> values = new Stack<>();
        for (int i=0; i < s.length(); i++) {
            if (s.charAt(i) == '(' || s.charAt(i) == '[' || s.charAt(i) == '{') {
                values.push(s.charAt(i));
            }

            if ((s.charAt(i) == ')' && values.peek() == '(') || (s.charAt(i) == ']' && values.peek() == '[') || ((s.charAt(i) == '}') && values.peek() == '{')) {
                values.pop();
            }
        }
        if (values.empty()) {
            return true;
        } else {
            return false;
        }
    }
}

    This passes all the test cases, however when I press submit, it gives me the following error:

    java.util.EmptyStackException

    at line 103, java.base/java.util.Stack.peek
    at line 11, Solution.isValid
    at line 56, DriverSolution.helper
    at line 86, Driver.main

    After looking at the documentation for java.util.Stack, I've seen that under the method peek() it says:

    Throws:
    EmptyStackException - if this stack is empty.

    I understand it's to do with using peek() when the stack is empty, but I'm confused as to how to fix it since it somehow passed the tests before that. How do I fix this in my code?

    • java
    • exception
    • stack
    • throws
    Share Improve this question edited Mar 31 at 16:26 pxkaa asked Mar 31 at 16:24 pxkaapxkaa 11 bronze badge 5
    • 2 Perhaps there are test cases that Leetcode runs in addition to the ones it tells you about? It's easy enough to provoke that failure - just run with an input of ")" for example. – Jon Skeet Commented Mar 31 at 16:31
    • I see, it's trying to run "]", and since I've only told it to push opening parentheses, it's peeking/popping from an empty stack. Correct me if I'm wrong, but I think the way to fix this is by pushing every value in the string? Thank you! – pxkaa Commented Mar 31 at 16:37
    • 2 No, you shouldn't push in this case. I'm not going to walk you through how to fix this though. I'll just give you the hint that if you see a closing bracket of any kind when the stack is empty, you know the result. I'll give you a second hint that your code will give the wrong result for [)] as well... – Jon Skeet Commented Mar 31 at 16:57
    • When the source of a problem has a web page, such as might be the case with programming practice and challenge sites, it would be polite, and possibly helpful, to include a link to that page. leetcode/problems/valid-parentheses/description – Old Dog Programmer Commented Mar 31 at 22:57
    • You should also have an else after the first if. – user207421 Commented Apr 2 at 6:48
    Add a comment  | 

    2 Answers 2

    Reset to default 0

    The problem arises because when a closing parenthesis appears with values empty, then your code enters the second if and tries a peek on the empty stack, what you should do is take two different paths if values is empty or if it is not.

    public boolean isValid( String s ) {
   Stack<Character> values = new Stack<>();
   for( int i = 0; i < s.length(); i ++ ) {
      if( s.charAt( i ) == '(' || s.charAt( i ) == '[' || s.charAt( i ) == '{' ) {
         values.push( s.charAt( i ) );
      }
      if( ! values.isEmpty() ) {
         if(     s.charAt( i ) == ')' && values.peek() == '(' || 
                 s.charAt( i ) == ']' && values.peek() == '[' ||
                 s.charAt( i ) == '}' && values.peek() == '{' ) {
            values.pop();
         }
      }
      else {
         if(     s.charAt( i ) == ')' ||
                 s.charAt( i ) == ']' ||
                 s.charAt( i ) == '}' ) {

              // if we have a closing parenthesis and "values" is empty, the string is not valid.
            return false;
         }
      }
   }
   return true;
}

    On looking into this, it seems like you are running into a test case that specifically checks for this on submission. Leetcode has some basic test cases before the actual ones they run to consider a solution Submitted. @Marce has put the code already.

    I would like to summarize that in your code you need to check values.isEmpty() before you call peek. With respect to the problem, it is basically failed if the stack is empty before you process the closing bracket.

    Pro tip: consider changing your return to return values.isEmpty();

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