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Binary Search (Binary Search) Algorithm a cikin PHP: Bayani, Matakai da Misali

Algorithm din Binciken Binary hanya ce mai inganci don nemo takamaiman ƙima a cikin tsararrun tsararru. Wannan hanya tana raba tsararrun zuwa ƙananan sassa kuma tana ci gaba da kwatanta ƙimar a tsakiyar kewayon bincike tare da ƙimar manufa. Idan ƙimar ta yi daidai, ana samun ƙimar da ake so; in ba haka ba, algorithm ya ci gaba da ƙaddamar da kewayon bincike kuma yana maimaita tsari har sai an sami ƙimar ko ba a bar ƙarin abubuwa don bincika ba.

Matakai:

  1. Fara kewayon bincike: Fara da zaɓar kewayon bincike daga matsayi na farko left  zuwa matsayi na ƙarshe right  na tsararru.
  2. Nemo tsakiyar tsakiya: Ƙididdige wurin tsakiya ta hanyar matsakaici left da matsayi na dama; wannan shine tsakiyar zangon bincike.
  3. Kwatanta dabi'u: Kwatanta ƙima a tsakiya tare da ƙimar manufa.
  4. Sarrafa sakamakon kwatance: Idan ƙima a tsakiya ta yi daidai da ƙimar manufa, mayar da wannan matsayi. Idan darajar a tsakiya ta kasa da ƙimar manufa, sabunta matsayin hagu zuwa tsakiya + 1 don bincika rabin dama. Idan darajar a tsakiyar tsakiya ta fi darajar manufa, sabunta matsayi na dama zuwa tsakiya- 1 don bincika rabi na hagu.
  5. Maimaita: Maimaita matakai 2 zuwa 4 har sai an sami ƙimar ko babu ƙarin abubuwan da za a bincika left > right.

Abũbuwan amfãni da rashin amfani

Amfani:

  • Ingantacciyar aiki: Tsararren lokaci na algorithm shine O(log n), yana mai da shi inganci sosai don sarrafa manyan bayanai.
  • Mai tasiri ga manyan bayanan bayanai: Binciken Binary yana da tasiri wajen rage adadin abubuwan da za a bincika da sauri don manyan bayanan bayanai.

Rashin hasara:

  • Ana amfani da shi kawai don tsararrun tsararraki: Algorithm ɗin yana aiki ne kawai akan tsararrun tsararru.
  • Adadin matakan matakai: Adadin matakan da ake buƙata don nemo ƙimar ya dogara da matsayinsa a cikin tsararru, kuma yana iya ɗaukar matakai da yawa don ƙimar kusa da ƙarshen.

Misali: Binciken Binary don gano ƙimar 12 a cikin tsararrun tsararru a cikin PHP 

function binarySearch($arr, $target) {  
    $left = 0;  
    $right = count($arr)- 1;  
  
    while($left <= $right) {  
        $mid = floor(($left + $right) / 2);  
  
        if($arr[$mid] == $target) {  
            return $mid; // Return the position of the value  
        } elseif($arr[$mid] < $target) {  
            $left = $mid + 1;  
        } else {  
            $right = $mid- 1;  
        }  
    }  
  
    return -1; // Value not found  
}  
  
$array = [2, 5, 8, 12, 15, 20, 30];  
$targetValue = 12;  
  
$result = binarySearch($array, $targetValue);  
  
if($result != -1) {  
    echo "Value $targetValue found at position $result.";  
} else {  
    echo "Value $targetValue not found in the array.";  
}

Bayanin Misali

  1. Muna farawa da kewayon bincike na farko daga matsayi na farko left = 0 zuwa matsayi na ƙarshe right = 6  na tsararru.
  2. Muna lissafin tsakiyar tsakiya(tsakiyar) ta hanyar matsakaicin matsayi na hagu da dama; mid = 3. Darajar a tsakiyar shine 12.
  3. Muna kwatanta ƙimar a mid(12) tare da ƙimar manufa(12) kuma sami wasa, don haka mu koma matsayi na 3.
  4. Algorithm ya ƙare, kuma muna fitar da sakamakon "Value 12 da aka samo a matsayi na 3."