Python中的查找算法代码实例

def sequential_search(lis, key):
    length = len(lis)
    for i in range(length):
        print(lis[i], key)
        if lis[i] == key:
            return i
    return False
if __name__ == '__main__':
    LIST = [1, 5, 8, 123, 22, 54, 7, 99, 300, 222]
    result = sequential_search(LIST, 123)
    print(result)

lst = [11, 22, 33, 44, 55, 66, 77, 88, 99, 123, 234, 345, 456, 567, 678, 789]
def func(alist, data):
    first = 0
    last = len(alist) - 1
    while first <= last:
        mid = (last + first) // 2
        if alist[mid] > data:
            last = mid - 1
        elif alist[mid] < data:
            first = mid + 1
        else:
            return mid
    return -1
print(func(lst, 678))

def binary_search(lis, key):
    low = 0
    high = len(lis) - 1
    while low < high:
        mid = low + int((high - low) * (key - lis[low]) / (lis[high] - lis[low]))
        if key < lis[mid]:
            high = mid - 1
        elif key > lis[mid]:
            low = mid + 1
        else:
            return mid
    return False
LIST = [1, 5, 7, 8, 22, 54, 99, 123, 200, 222, 444]
result = binary_search(LIST, 99)
print(result)