@H_404_0@<span style="background-color: #ccffcc">
如下所示：
<div class="jb51code">
<pre class="brush:PHP;">
<?PHP
/**
- title: 判断表达式中括号是否匹配
- Description: () 匹配 )(不匹配 利用压栈和出栈
- @author Mr Lv
/
function isValid($expstr) {
$temp = array();
for ($i=0; $i<strlen($expstr); $i++) {
$ch = $expstr[$i];
switch($ch) {
case '(':
array_push($temp,'(');
break;
case ')':
if (empty($temp) || array_pop($temp) != '(') {
return "缺少左括号（";
}
}
}
return empty($temp) == true ? "表达式匹配" : "缺少右括号）";
}
$expstrA = "(1+3(64)-(2+3))()(";
$expstrB = "(1+3(64)-(2+3))()";
$expstrC = "(1+3(64)-(2+3)))";
echo isValid($expstrA);
echo "
";
echo isValid($expstrB);
echo "
";
echo isValid($expstrC);
?>
