leetcode/two_sum.py

import pytest


def twoSum(nums, target):
    lens = len(nums)
    j=-1
    for i in range(lens):
        if (target - nums[i]) in nums:
            # 如果num2=num1,且nums中只出现了一次，说明找到是num1本身。
            if (nums.count(target - nums[i]) == 1) & (target - nums[i] == nums[i]):
                continue
            else:
                # index(x,i+1)是从num1后的序列后找num2
                j = nums.index(target - nums[i],i+1)
                break
    if j>0:
        return [i,j]
    else:
        return []

#
# def twoSum(nums, target):
#     hashmap={}
#     for ind,num in enumerate(nums):
#         hashmap[num] = ind
#     for i,num in enumerate(nums):
#         j = hashmap.get(target - num)
#         if j is not None and i!=j:
#             return [i,j]


def test_case_1():
    res = twoSum([2, 3, 1, 5, 8], 6)
    expect = [2, 3]
    assert expect == res