【开发者笔记】二分法查找

#python code
def binary_serach(arr,st,end,tar):
    mid = st + end
    mid = mid // 2
    if st > end:
        return False
    elif tar == arr[mid]:
        return True
    elif tar < arr[st] or tar > arr[end]:
        return False
    elif tar < arr[mid]:
        return binary_serach(arr,st,mid,tar)
    elif tar > arr[mid]:
        return binary_serach(arr,mid+1,end,tar)
    else:
        return False

if __name__ == "__main__":
    l = [1,3,5,6,8,9,12,15,17,23,45]
    print(l)
    print("target: %s, result: %s" % (0, binary_serach(l, 0, len(l) - 1, 0)))
    print("target: %s, result: %s" % (1, binary_serach(l, 0, len(l) - 1, 1)))
    print("target: %s, result: %s" % (2, binary_serach(l, 0, len(l) - 1, 2)))
    print("target: %s, result: %s" % (3, binary_serach(l, 0, len(l) - 1, 3)))
    print("target: %s, result: %s" % (23, binary_serach(l, 0, len(l) - 1, 23)))
    print("target: %s, result: %s" % (45, binary_serach(l, 0, len(l) - 1, 45)))
    print("target: %s, result: %s" % (46, binary_serach(l, 0, len(l) - 1, 46)))