語言：python Two Sum

分析：return indices of the two numbers。顯然，該問題應該採用類似HashMap方法解決，而python中字典這一資料型別正相當於HashMap，應該以數字number為鍵key，indices為值value。

class Solution:
    def twoSum(self, nums, target):
        """
        :type nums: List[int]
        :type target: int
        :rtype: List[int]
        """
        # one-pass
        dict = {}
        for i, num in enumerate(nums):
            res = target - num
            if res in dict:
                return [dict[res], i]
            dict[num] = i;
 

試問如何除錯程式碼段呢？顯然補全完整！

舉個栗子：

import json
import sys
import io


class Solution:
    def twoSum(self, nums, target):
        """
        :type nums: List[int]
        :type target: int
        :rtype: List[int]
        """
        dic = {}
        for i, num in enumerate(nums):
            res = target - num
            if res in dic:
                return [dic[res], i]
            dic[num] = i


def stringToIntegerList(input):
    return json.loads(input)


def integerListToString(nums, len_of_list=None):
    if not len_of_list:
        len_of_list = len(nums)
    return json.dumps(nums[:len_of_list])


def main():
    def readlines():
        for line in io.TextIOWrapper(sys.stdin.buffer, encoding='utf-8'):
            yield line.strip('\n')

    lines = readlines()
    while True:
        try:
            line = next(lines)
            nums = stringToIntegerList(line)
            line = next(lines)
            target = int(line)

            ret = Solution().twoSum(nums, target)

            out = integerListToString(ret)
            print(out)
        except StopIteration:
            break


if __name__ == '__main__':
    main()
 

其實這個程式碼段現成的，可以拷到本地環境除錯除錯。