Write a function:
def solution(A)
that, given an array A of N integers, returns the smallest positive integer (greater than 0) that does not occur in A.
For example, given A = [1, 3, 6, 4, 1, 2], the function should return 5.
Given A = [1, 2, 3], the function should return 4.
Given A = [−1, −3], the function should return 1.
Write an efficient algorithm for the following assumptions:
- N is an integer within the range [1..100,000];
- each element of array A is an integer within the range [−1,000,000..1,000,000].
def solution(A):
ret = 1
c = len(A)
for i in range(0, c, 1):
if A[i] <= 0:
continue
if ret not in A:
return ret
else:
ret += 1
return ret
python list in 时间复杂度 列表元素存在性