mirror of
https://github.com/renbaoshuo/S2OJ.git
synced 2024-12-23 11:31:52 +00:00
758 lines
17 KiB
PHP
758 lines
17 KiB
PHP
<?php
|
||
|
||
// this class depends on getUOJConf from uoj-judger-lib.php sometimes
|
||
// be sure to include the lib
|
||
// TODO: move getUOJConf into a static class independent of uoj-judger-lib.php
|
||
|
||
class UOJProblem {
|
||
use UOJDataTrait;
|
||
use UOJArticleTrait;
|
||
|
||
public static array $difficulty = [
|
||
800,
|
||
1000,
|
||
1200,
|
||
1400,
|
||
1600,
|
||
1800,
|
||
1900,
|
||
2000,
|
||
2100,
|
||
2200,
|
||
2300,
|
||
2400,
|
||
2500,
|
||
2600,
|
||
2700,
|
||
2900,
|
||
3100,
|
||
3300,
|
||
3500,
|
||
];
|
||
|
||
public static array $difficulty_color = [
|
||
800 => '#008000',
|
||
1000 => '#008000',
|
||
1200 => '#00c0c0',
|
||
1400 => '#00c0c0',
|
||
1600 => '#0000ff',
|
||
1800 => '#0000ff',
|
||
1900 => '#0000ff',
|
||
2000 => '#aa00aa',
|
||
2100 => '#aa00aa',
|
||
2200 => '#aa00aa',
|
||
2300 => '#ff8000',
|
||
2400 => '#ff8000',
|
||
2500 => '#ff8000',
|
||
2600 => '#ff0000',
|
||
2700 => '#ff0000',
|
||
2900 => '#ff0000',
|
||
3100 => '#aa0000',
|
||
3300 => '#aa0000',
|
||
3500 => '#aa0000',
|
||
];
|
||
|
||
public static array $categories = [
|
||
'算法基础' => [
|
||
'暴力',
|
||
'枚举',
|
||
'模拟',
|
||
'递归与分治',
|
||
'贪心',
|
||
'排序',
|
||
'前缀和与差分',
|
||
'二分',
|
||
'倍增',
|
||
'构造',
|
||
'打表',
|
||
],
|
||
'搜索' => [
|
||
'深度优先搜索',
|
||
'广度优先搜索',
|
||
'双向搜索',
|
||
'启发式搜索',
|
||
'A*',
|
||
'IDA*',
|
||
'迭代加深',
|
||
'回溯法',
|
||
'Dancing Links',
|
||
],
|
||
'动态规划' => [
|
||
'记忆化搜索',
|
||
'线性 DP',
|
||
'背包 DP',
|
||
'区间 DP',
|
||
'树形 DP',
|
||
'状压 DP',
|
||
'数位 DP',
|
||
'DAG 上 DP',
|
||
'插头 DP',
|
||
'概率 DP',
|
||
'单调队列优化 DP',
|
||
'斜率优化 DP',
|
||
'四边形不等式优化 DP',
|
||
],
|
||
'计算几何' => [
|
||
'Pick 定理',
|
||
'三角剖分',
|
||
'凸包',
|
||
'扫描线',
|
||
'旋转卡壳',
|
||
'半平面交',
|
||
'平面最近点对',
|
||
'随机增量法',
|
||
'反演变换',
|
||
],
|
||
'数学' => [
|
||
'位运算',
|
||
'快速幂',
|
||
'高精度',
|
||
'生成函数',
|
||
'指数生成函数',
|
||
'向量',
|
||
'矩阵',
|
||
'高斯消元',
|
||
'线性基',
|
||
'线性规划',
|
||
'容斥',
|
||
'组合计数',
|
||
'离散对数',
|
||
'单纯形算法',
|
||
'概率',
|
||
'置换群',
|
||
'斐波那契数列',
|
||
'牛顿迭代法',
|
||
'数值积分',
|
||
'分块打表',
|
||
],
|
||
'数论' => [
|
||
'最大公约数',
|
||
'分解质因数',
|
||
'欧拉函数',
|
||
'筛法',
|
||
'欧拉定理',
|
||
'费马小定理',
|
||
'类欧几里得算法',
|
||
'翡蜀定理',
|
||
'乘法逆元',
|
||
'线性同余方程',
|
||
'Meissel-Lehmer 算法',
|
||
'二次剩余',
|
||
'BSGS',
|
||
'原根',
|
||
'卢卡斯定理',
|
||
'莫比乌斯反演',
|
||
'拉格朗日反演',
|
||
'杜教筛',
|
||
'Powerful Number 筛',
|
||
'Min_25 筛',
|
||
'洲阁筛',
|
||
'连分数',
|
||
'Stern-Brocot 数与 Farey 序列',
|
||
'Pell 方程',
|
||
],
|
||
'字符串' => [
|
||
'字符串哈希',
|
||
'字典树',
|
||
'KMP',
|
||
'Boyer-Moore',
|
||
'Z 函数（扩展 KMP）',
|
||
'AC 自动机',
|
||
'后缀数组',
|
||
'后缀自动机',
|
||
'后缀平衡树',
|
||
'广义后缀自动机',
|
||
'Manacher',
|
||
'回文树',
|
||
'序列自动机',
|
||
'最小表示法',
|
||
'Lyndon 分解',
|
||
],
|
||
'图论' => [
|
||
'拓扑排序',
|
||
'最短路',
|
||
'K 短路',
|
||
'同余最短路',
|
||
'虚树',
|
||
'树分治',
|
||
'动态树分治',
|
||
'树哈希',
|
||
'树上启发式合并',
|
||
'AHU 算法',
|
||
'矩阵树定理',
|
||
'最小生成树',
|
||
'最小树形图',
|
||
'最小直径生成树',
|
||
'斯坦纳树',
|
||
'拆点',
|
||
'差分约束',
|
||
'强连通分量',
|
||
'双连通分量',
|
||
'割点与桥',
|
||
'圆方树',
|
||
'2-SAT',
|
||
'欧拉图',
|
||
'哈密顿图',
|
||
'最小环',
|
||
'平面图',
|
||
'网络流',
|
||
'最大流',
|
||
'最小割',
|
||
'费用流',
|
||
'上下界网络流',
|
||
'Stoer-Wagner 算法',
|
||
'二分图',
|
||
'二分图最大匹配',
|
||
'二分图最大权匹配',
|
||
'一般图最大匹配',
|
||
'一般图最大权匹配',
|
||
'Prufer 序列',
|
||
'LGV 引理',
|
||
'弦图',
|
||
],
|
||
'组合数学' => [
|
||
'排列组合',
|
||
'卡特兰数',
|
||
'斯特林数',
|
||
'贝尔数',
|
||
'伯努利数',
|
||
'康托展开',
|
||
'容斥原理',
|
||
'抽屉原理',
|
||
'欧拉数',
|
||
],
|
||
'数据结构' => [
|
||
'栈',
|
||
'队列',
|
||
'链表',
|
||
'哈希表',
|
||
'并查集',
|
||
'二叉堆',
|
||
'配对堆',
|
||
'树状数组',
|
||
'线段树',
|
||
'平衡树',
|
||
'左偏树',
|
||
'块状数组',
|
||
'块状链表',
|
||
'树分块',
|
||
'Sqrt Tree',
|
||
'可持久化数据结构',
|
||
'单调栈',
|
||
'单调队列',
|
||
'ST 表',
|
||
'树套树',
|
||
'李超线段树',
|
||
'区间最值操作与区间历史最值',
|
||
'划分树',
|
||
'跳表',
|
||
'K-D Tree',
|
||
'珂朵莉树',
|
||
'动态树',
|
||
'析合树',
|
||
],
|
||
'多项式' => [
|
||
'拉格朗日插值',
|
||
'快速傅里叶变换',
|
||
'快速数论变换',
|
||
'快速沃尔什变换',
|
||
'多项式求逆',
|
||
'多项式开方',
|
||
'多项式除法与取模',
|
||
'多项式对数函数与指数函数',
|
||
'多项式牛顿迭代',
|
||
'多项式多点求值与快速插值',
|
||
'多项式三角函数',
|
||
'多项式反三角函数',
|
||
'常系数齐次线性递推',
|
||
],
|
||
'博弈论' => [
|
||
'不平等博弈',
|
||
'SG 函数',
|
||
'Nim 游戏',
|
||
'Anti-Nim',
|
||
'纳什均衡',
|
||
],
|
||
'杂项' => [
|
||
'构造',
|
||
'离散化',
|
||
'CDQ 分治',
|
||
'整体二分',
|
||
'分块',
|
||
'莫队',
|
||
'分数规划',
|
||
'随机化',
|
||
'模拟退火',
|
||
'爬山法',
|
||
'悬线法',
|
||
'编译原理',
|
||
'复杂度分析',
|
||
'语义分析',
|
||
'底层优化',
|
||
],
|
||
];
|
||
|
||
public static function query($id) {
|
||
if (!isset($id) || !validateUInt($id)) {
|
||
return null;
|
||
}
|
||
$info = DB::selectFirst([
|
||
"select * from problems",
|
||
"where", ['id' => $id]
|
||
]);
|
||
if (!$info) {
|
||
return null;
|
||
}
|
||
return new UOJProblem($info);
|
||
}
|
||
|
||
public static function upgradeToContestProblem() {
|
||
return (new UOJContestProblem(self::cur()->info, UOJContest::cur()))->setAsCur()->valid();
|
||
}
|
||
|
||
public static function userCanManageSomeProblem(array $user = null) {
|
||
if (!$user) {
|
||
return false;
|
||
}
|
||
|
||
if (isSuperUser($user) || UOJUser::checkPermission($user, 'problems.manage')) {
|
||
return true;
|
||
}
|
||
|
||
return DB::selectFirst([
|
||
DB::lc(), "select 1 from problems_permissions",
|
||
"where", [
|
||
'username' => $user['username']
|
||
], DB::limit(1)
|
||
]) != null || DB::selectFirst([
|
||
DB::lc(), "select 1 from problems",
|
||
"where", [
|
||
"uploader" => $user['username'],
|
||
], DB::limit(1),
|
||
]) != null;
|
||
}
|
||
|
||
public static function userCanCreateProblem(array $user = null) {
|
||
if (!$user) {
|
||
return false;
|
||
}
|
||
|
||
return isSuperUser($user) || UOJUser::checkPermission($user, 'problems.create');
|
||
}
|
||
|
||
public function __construct($info) {
|
||
$this->info = $info;
|
||
}
|
||
|
||
public function getTitle(array $cfg = []) {
|
||
$cfg += [
|
||
'with' => 'id',
|
||
'simplify' => false
|
||
];
|
||
$title = $this->info['title'];
|
||
if ($cfg['simplify']) {
|
||
$title = trim($title);
|
||
$title = mb_ereg_replace('^(\[[^\]]*\]|【[^】]*】)', '', $title);
|
||
$title = trim($title);
|
||
}
|
||
if ($cfg['with'] == 'id') {
|
||
return "#{$this->info['id']}. {$title}";
|
||
} else {
|
||
return $title;
|
||
}
|
||
}
|
||
|
||
public function getUri($where = '') {
|
||
return "/problem/{$this->info['id']}{$where}";
|
||
}
|
||
|
||
public function getLink(array $cfg = []) {
|
||
return HTML::link($this->getUri(), $this->getTitle($cfg), ['escape' => false]);
|
||
}
|
||
|
||
public function getAttachmentUri() {
|
||
return '/download/problem/' . $this->info['id'] . '/attachment.zip';
|
||
}
|
||
|
||
public function getMainDataUri() {
|
||
return '/download/problem/' . $this->info['id'] . '/data.zip';
|
||
}
|
||
|
||
public function getUploaderLink() {
|
||
return UOJUser::getLink($this->info['uploader'] ?: "root");
|
||
}
|
||
|
||
public function getProviderLink() {
|
||
if ($this->info['type'] == 'local') {
|
||
return HTML::tag('a', ['href' => HTML::url('/')], UOJConfig::$data['profile']['oj-name-short']);
|
||
}
|
||
|
||
$remote_oj = $this->getExtraConfig('remote_online_judge');
|
||
$remote_id = $this->getExtraConfig('remote_problem_id');
|
||
|
||
if (!$remote_oj || !array_key_exists($remote_oj, UOJRemoteProblem::$providers)) {
|
||
return 'Error';
|
||
}
|
||
|
||
$provider = UOJRemoteProblem::$providers[$remote_oj];
|
||
|
||
return HTML::tag('a', [
|
||
'href' => UOJRemoteProblem::getProblemRemoteUrl($remote_oj, $remote_id),
|
||
'target' => '_blank'
|
||
], $provider['name']);
|
||
}
|
||
|
||
public function getDifficultyHTML() {
|
||
$difficulty = (int)$this->info['difficulty'];
|
||
$difficulty_text = in_array($difficulty, static::$difficulty) ? $difficulty : '?';
|
||
$difficulty_color = in_array($difficulty, static::$difficulty) ? static::$difficulty_color[$difficulty] : '#7e7e7e';
|
||
|
||
return HTML::tag('span', ['class' => 'uoj-difficulty', 'style' => "color: $difficulty_color"], $difficulty_text);
|
||
}
|
||
|
||
public function findInContests() {
|
||
$res = DB::selectAll([
|
||
"select contest_id from contests_problems",
|
||
"where", ['problem_id' => $this->info['id']]
|
||
]);
|
||
$cps = [];
|
||
foreach ($res as $row) {
|
||
$cp = new UOJContestProblem($this->info, UOJContest::query($row['contest_id']));
|
||
if ($cp->valid()) {
|
||
$cps[] = $cp;
|
||
}
|
||
}
|
||
return $cps;
|
||
}
|
||
|
||
public function userCanClickZan(array $user = null) {
|
||
if ($this->userCanView($user)) {
|
||
return true;
|
||
}
|
||
foreach ($this->findInContests() as $cp) {
|
||
if ($cp->userCanClickZan($user)) {
|
||
return true;
|
||
}
|
||
}
|
||
return false;
|
||
}
|
||
|
||
public function getZanBlock() {
|
||
return ClickZans::getBlock('P', $this->info['id'], $this->info['zan']);
|
||
}
|
||
|
||
public function getSubmissionRequirement() {
|
||
return json_decode($this->info['submission_requirement'], true);
|
||
}
|
||
public function getExtraConfig($key = null) {
|
||
$extra_config = json_decode($this->info['extra_config'], true);
|
||
|
||
$extra_config += [
|
||
'view_content_type' => 'ALL',
|
||
'view_all_details_type' => 'ALL',
|
||
'view_details_type' => 'ALL',
|
||
'view_solution_type' => 'ALL',
|
||
'submit_solution_type' => 'ALL_AFTER_AC',
|
||
'need_to_review_hack' => false,
|
||
'add_hack_as' => 'ex_test',
|
||
];
|
||
|
||
return $key === null ? $extra_config : $extra_config[$key];
|
||
}
|
||
public function getCustomTestRequirement() {
|
||
$extra_config = json_decode($this->info['extra_config'], true);
|
||
|
||
if (isset($extra_config['custom_test_requirement'])) {
|
||
return $extra_config['custom_test_requirement'];
|
||
}
|
||
|
||
$answer = [
|
||
'name' => 'answer',
|
||
'type' => 'source code',
|
||
'file_name' => 'answer.code'
|
||
];
|
||
foreach ($this->getSubmissionRequirement() as $req) {
|
||
if ($req['name'] == 'answer' && $req['type'] == 'source code' && isset($req['languages'])) {
|
||
$answer['languages'] = $req['languages'];
|
||
}
|
||
}
|
||
return [
|
||
$answer, [
|
||
'name' => 'input',
|
||
'type' => 'text',
|
||
'file_name' => 'input.txt'
|
||
]
|
||
];
|
||
}
|
||
|
||
public function userCanView(array $user = null, array $cfg = []) {
|
||
$cfg += ['ensure' => false];
|
||
|
||
if ($this->info['is_hidden'] && !$this->userCanManage($user)) {
|
||
$cfg['ensure'] && UOJResponse::page404();
|
||
return false;
|
||
}
|
||
|
||
if (!UOJUser::checkPermission($user, 'problems.view')) {
|
||
$cfg['ensure'] && UOJResponse::page403();
|
||
return false;
|
||
}
|
||
|
||
return true;
|
||
}
|
||
|
||
/**
|
||
* Get a SQL cause to determine whether a user can view a problem
|
||
* Need to be consistent with the member function userCanView
|
||
*/
|
||
public static function sqlForUserCanView(array $user = null) {
|
||
if (isSuperUser($user) || UOJUser::checkPermission($user, 'problems.manage')) {
|
||
return "(1)";
|
||
} elseif (UOJProblem::userCanManageSomeProblem($user)) {
|
||
return DB::lor([
|
||
"problems.is_hidden" => false,
|
||
DB::land([
|
||
"problems.is_hidden" => true,
|
||
DB::lor([
|
||
[
|
||
"problems.id", "in", DB::rawbracket([
|
||
"select problem_id from problems_permissions",
|
||
"where", ["username" => $user['username']]
|
||
])
|
||
],
|
||
[
|
||
"problems.id", "in", DB::rawbracket([
|
||
"select problem_id from problems",
|
||
"where", ["uploader" => $user['username']]
|
||
])
|
||
],
|
||
])
|
||
])
|
||
]);
|
||
} else {
|
||
return "(problems.is_hidden = false)";
|
||
}
|
||
}
|
||
|
||
public function isUserOwnProblem(array $user = null) {
|
||
if (!$user) {
|
||
return false;
|
||
}
|
||
return $user['username'] === $this->info['uploader'];
|
||
}
|
||
|
||
public function userPermissionCodeCheck(array $user = null, $perm_code) {
|
||
switch ($perm_code) {
|
||
case 'ALL':
|
||
return true;
|
||
case 'ALL_AFTER_AC':
|
||
return $this->userHasAC($user);
|
||
case 'NONE':
|
||
return false;
|
||
default:
|
||
return null;
|
||
}
|
||
}
|
||
|
||
public function userCanUploadSubmissionViaZip(array $user = null) {
|
||
$submission_requirement = $this->getSubmissionRequirement();
|
||
|
||
if (empty($submission_requirement)) return false;
|
||
|
||
foreach ($submission_requirement as $req) {
|
||
if ($req['type'] == 'source code') {
|
||
return false;
|
||
}
|
||
}
|
||
|
||
return true;
|
||
}
|
||
|
||
public function userCanDownloadAttachments(array $user = null) {
|
||
if ($this->userCanView($user)) {
|
||
return true;
|
||
}
|
||
foreach ($this->findInContests() as $cp) {
|
||
if ($cp->userCanDownloadAttachments($user)) {
|
||
return true;
|
||
}
|
||
}
|
||
return false;
|
||
}
|
||
|
||
public function userCanManage(array $user = null) {
|
||
if (!$user) {
|
||
return false;
|
||
}
|
||
|
||
if (isSuperUser($user) || $this->isUserOwnProblem($user) || UOJUser::checkPermission($user, 'problems.manage')) {
|
||
return true;
|
||
}
|
||
|
||
return DB::selectFirst([
|
||
DB::lc(), "select 1 from problems_permissions",
|
||
"where", [
|
||
'username' => $user['username'],
|
||
'problem_id' => $this->info['id']
|
||
]
|
||
]) != null;
|
||
}
|
||
|
||
public function userCanDownloadTestData(array $user = null) {
|
||
if ($this->userCanManage($user)) {
|
||
return true;
|
||
}
|
||
|
||
if (!UOJUser::checkPermission($user, 'problems.download_testdata')) {
|
||
return false;
|
||
}
|
||
|
||
foreach ($this->findInContests() as $cp) {
|
||
if ($cp->contest->userHasRegistered($user) && $cp->contest->progress() == CONTEST_IN_PROGRESS) {
|
||
return false;
|
||
}
|
||
}
|
||
|
||
return true;
|
||
}
|
||
|
||
public function preHackCheck(array $user = null) {
|
||
return $this->info['hackable'] && (!$user || $this->userCanView($user));
|
||
}
|
||
|
||
public function needToReviewHack() {
|
||
return $this->getExtraConfig('need_to_review_hack');
|
||
}
|
||
|
||
public function userHasAC(array $user = null) {
|
||
if (!$user) {
|
||
return false;
|
||
}
|
||
return DB::selectFirst([
|
||
DB::lc(), "select 1 from best_ac_submissions",
|
||
"where", [
|
||
'submitter' => $user['username'],
|
||
'problem_id' => $this->info['id']
|
||
]
|
||
]) != null;
|
||
}
|
||
|
||
public function preSubmitCheck() {
|
||
return true;
|
||
}
|
||
|
||
public function additionalSubmissionComponentsCannotBeSeenByUser(array $user = null, UOJSubmission $submission) {
|
||
foreach ($this->findInContests() as $cp) {
|
||
if ($cp->contest->userHasRegistered($user) && $cp->contest->progress() == CONTEST_IN_PROGRESS) {
|
||
if ($submission->userIsSubmitter($user)) {
|
||
if ($cp->getJudgeTypeInContest() == 'no-details') {
|
||
return ['low_level_details'];
|
||
} else {
|
||
return [];
|
||
}
|
||
} else {
|
||
return ['content', 'high_level_details', 'low_level_details'];
|
||
}
|
||
}
|
||
}
|
||
|
||
return [];
|
||
}
|
||
|
||
public function getDataFolderPath() {
|
||
return "/var/uoj_data/{$this->info['id']}";
|
||
}
|
||
|
||
public function getUploadFolderPath() {
|
||
return "/var/uoj_data/upload/{$this->info['id']}";
|
||
}
|
||
|
||
public function getDataZipPath() {
|
||
return "/var/uoj_data/{$this->info['id']}.zip";
|
||
}
|
||
|
||
public function getDataFilePath($name = '') {
|
||
// return "zip://{$this->getDataZipPath()}#{$this->info['id']}/$name";
|
||
return "{$this->getDataFolderPath()}/$name";
|
||
}
|
||
|
||
public function getUploadFilePath($name = '') {
|
||
return "{$this->getUploadFolderPath()}/$name";
|
||
}
|
||
|
||
public function getResourcesFolderPath() {
|
||
return UOJContext::storagePath() . "/problem_resources/" . $this->info['id'];
|
||
}
|
||
|
||
public function getResourcesPath($name = '') {
|
||
return "{$this->getResourcesFolderPath()}/$name";
|
||
}
|
||
|
||
public function getResourcesBaseUri() {
|
||
return "/problem/{$this->info['id']}/resources";
|
||
}
|
||
|
||
public function getResourcesUri($name = '') {
|
||
return "{$this->getResourcesBaseUri()}/{$name}";
|
||
}
|
||
|
||
public function getProblemConfArray(string $where = 'data') {
|
||
if ($where === 'data') {
|
||
$conf = UOJProblemConf::getFromFile($this->getDataFilePath('problem.conf'));
|
||
|
||
return $conf instanceof UOJProblemConf ? $conf->conf : $conf;
|
||
} else {
|
||
return null;
|
||
}
|
||
}
|
||
|
||
public function getProblemConf(string $where = 'data') {
|
||
if ($where === 'data') {
|
||
return UOJProblemConf::getFromFile($this->getDataFilePath('problem.conf'));
|
||
} else {
|
||
return null;
|
||
}
|
||
}
|
||
|
||
public function getNonTraditionalJudgeType() {
|
||
$conf = $this->getProblemConf();
|
||
if (!($conf instanceof UOJProblemConf)) {
|
||
return false;
|
||
}
|
||
return $conf->getNonTraditionalJudgeType();
|
||
}
|
||
|
||
public function syncData($user = null) {
|
||
return (new UOJProblemDataSynchronizer($this, $user))->sync();
|
||
}
|
||
|
||
public function addHackPoint($uploaded_input_file, $uploaded_output_file, $reason = null, $user = null) {
|
||
if ($reason === null) {
|
||
if (UOJHack::cur()) {
|
||
$reason = [
|
||
'rejudge' => '自动重测本题所有获得100分的提交记录',
|
||
'hack_url' => HTML::url(UOJHack::cur()->getUri())
|
||
];
|
||
} else {
|
||
$reason = [];
|
||
}
|
||
}
|
||
|
||
return (new UOJProblemDataSynchronizer($this, $user))->addHackPoint($uploaded_input_file, $uploaded_output_file, $reason);
|
||
}
|
||
|
||
public function uploadDataViaZipFile($new_data_zip) {
|
||
return (new UOJProblemDataSynchronizer($this))->upload($new_data_zip);
|
||
}
|
||
|
||
public function updateProblemConf($new_problem_conf) {
|
||
return (new UOJProblemDataSynchronizer($this))->updateProblemConf($new_problem_conf);
|
||
}
|
||
}
|
||
|
||
UOJProblem::$table_for_content = 'problems_contents';
|
||
UOJProblem::$key_for_content = 'id';
|
||
UOJProblem::$fields_for_content = ['*'];
|
||
UOJProblem::$table_for_tags = 'problems_tags';
|
||
UOJProblem::$key_for_tags = 'problem_id';
|