Binary search golek target ing array sing disortir kanthi nggawe search range bola-bali. Saben perbandingan ngilangke separo saka elemen sing isih ana, menehi wektu O(log n).
Padha tengah elemen. Yen padha karo target, rampung. Yen target luwih cilik, goleki sisih kiwa; yen luwih gedhe, goleki sisih tengen. Balekno nganti ketemu utawa range kosong.
def binary_search(arr, target):
lo, hi = 0, len(arr) - 1
while lo <= hi:
mid = (lo + hi) // 2 # middle index
if arr[mid] == target:
return mid # found it
elif arr[mid] < target:
lo = mid + 1 # discard left half
else:
hi = mid - 1 # discard right half
return -1 # not present
binary_search([1, 3, 5, 7, 9], 7) # -> 3
Search 7 in [1,3,5,7,9]
lo=0 hi=4 mid=2 -> 5 < 7 => lo=3
lo=3 hi=4 mid=3 -> 7 == 7 => return 3
Input kudu disortir — salawane asil ora ana teges. Ati-ati bug off-by-one ing lo/hi lan integer overflow ing sawetara basa (gunakake lo + (hi-lo)//2).
Nggawe search space setengah ngowahi pencarian siji yuta elemen dadi kira-kira 20 perbandingan.
Pola divide-and-conquer sastra mengko tampil maneh ing wit, database, lan akeh banget masalah wawancara.
Ngewangi siji requirement sing kerep — input sing disortir — njaga sampeyan saka bug halus klasik.
Pustaka pitakon wawancara IT kanthi jawaban rinci — saka Junior nganti Senior.
Nyumbang