PHP data structure and algorithm (PHP description) Search and binary search_PHP tutorial

Copy code The code is as follows:

/**
* Find
*
**/
// Order Find
function normal_search($arrData,$val) {
$len = count($arrData);
if($len == 0) return -1;
for($i = 0 ;$i < $len; $i++ ) {
echo "find No.",$i + 1," value = ",$arrData[$i]," is = ",$val,"? < ;br/>";
// Found
if($arrData[$i] == $val) return $i;
}
return -1;
}

//Test order search
$arrData = array(4,51,6,73,2,5,9,33,50,3,4,6,1,4,67);
echo normal_search($arrData,6),"
";
echo normal_search($arrData,66),"
";

// Two points Method search (search for ordered columns)
function binary_search($arrData,$val) {
$len = count($arrData);
if($len == 0) return -1 ;

$start = 0;
$end = $len - 1;

while($start <= $end) {
$middle = intval(($ start + $end)/2);
echo "start = ",$start," end = ",$end," middle = ",$middle,"
";
if ($arrData[$middle] == $val) {
return $middle;
} elseif ($arrData[$middle] > $val) {
$end = $middle - 1 ;
} elseif ($arrData[$middle] < $val) {
$start = $middle + 1;
}
}
return -1;
}

//Test binary search
$arrData = array(1,2,3,4,5,7,8,9,11,23,56,100,104,578,1000);
echo binary_search($ arrData,578),"
";
echo binary_search($arrData,66),"
";

http://www.bkjia.com/PHPjc/325529.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/325529.htmlTechArticleCopy the code as follows: ?php /*** Find * **/ // Sequential search function normal_search($arrData ,$val) { $len = count($arrData); if($len == 0) return -1; for($i = 0;$i $len; $i++...