Post

Two Sum II - Input Array Is Sorted

Posted Updated
By Seonghun Jung 1 min read

1. Problem Statement

2. Algorithm Design and Approach

3. Implementation

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class Solution
{
public:
    vector<int> twoSum(vector<int> &numbers, int target)
    {
        int minIndex = 0;
        int maxIndex = numbers.size() - 1;
        for (; minIndex != maxIndex;)
        {
            int temp = numbers[minIndex] + numbers[maxIndex];
            if (temp > target)
            {
                maxIndex--;
            }
            else if(temp < target)
            {
                minIndex++;
            }
            else
            {
                break;
            }
        }
        return vector<int>{minIndex + 1, maxIndex + 1};
    }
};

4. Example Walkthrough

5. Conclusion

  • for 대신 While 문 사용 고려
  • else if 대신 그냥 else만 쓰는게 더 시간단축
Algorithm, Two Pointers
c++ leet code
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