원하는 값(target) 찾기

정렬이 안되어 있을 때

arr = [5, 7, 8, 6, 3, 2, 1, 4, 9]
n = len(arr)
def search(target):
    for i in range(n):
        if arr[i] == target:
            return i
    return -1
print(search(1)) #=> 6

arr = [5, 7, 8, 6, 3, 2, 1, 4, 9]
def search(target):
    i = 0
    while i < n and arr[i] != target:
        i += 1
    if arr[i] == target:
        return i
    return -1
print(search(1)) #=> 6

정렬이 되어 있을 때

arr = [1, 2, 3, 5, 8, 9, 11, 13, 14]
n = len(arr)
def search(target):
    for i in range(n):
        if arr[i] == target:
            return i
    return -1
print(search(8)) #=> 4

arr = [1, 2, 3, 5, 8, 9, 11, 13, 14]
n = len(arr)
def search(target):
    i = 0
    while i < n and arr[i] <= target:
        if arr[i] == target:
            return i
        i += 1
    return -1
print(search(8)) #=> 4