PHP查找数组中最大值与最小值-白红宇

PHP查找数组中最大值与最小值

阅读量：5789 次

发布时间：2019-06-18

本文共 1377 字，大约阅读时间需要 4 分钟。


      $arr[$i]) {                 $cmpTime++;                 if($small > $arr[$i]) {                     $small = $arr[$i];                 }              } else {                 $big = $arr[$i];             }         }                  echo "ArrLeng: " . $count . "
";         echo "CmpTime: " . $cmpTime . "
";         echo "Big: " . $big . "
";         echo "Small: " . $small . "
";     }          $arr = array(4, 6, 8, 1, 5, 4, 3, 9, 11, 3, 22, 100, 55, 0, 4, -1, 31, 210, -10);     maxMin($arr); ?>

ArrLeng: 19
CmpTime: 29
Big: 210
Small: -10

这个方法是一个不稳定的查找，找的时候比较是n次，而最坏的时候比较是2n次，下面来看一个稳定的1.5n次比较的方法


      $arr[$i + 1]) {                $bigger = $arr[$i];                $smaller = $arr[$i + 1];             } else {                $bigger = $arr[$i + 1];                $smaller = $arr[$i];                }             $cmpTime++;                 if($bigger > $biggest) {                 $biggest = $bigger;             }             $cmpTime++;             if($smaller < $smallest) {                $smallest = $smaller;             }         }         echo "ArrLeng: " . $count . "
";         echo "CmpTime: " . $cmpTime . "
";         echo "Big: " . $biggest . "
";         echo "Small: " . $smallest . "
";     }          $arr = array(4, 6, 8, 1, 5, 4, 3, 9, 11, 3, 22, 100, 55, 0, 4, -1, 31, 210, -10);     maxMin($arr); ?>