LeetCode-228：Summary Ranges (總結範圍)

題目：

Given a sorted integer array without duplicates, return the summary of its ranges.

例子

Example 1:

Input: [0,1,2,4,5,7]
Output: ["0->2","4->5","7"]

Example 2:

Input: [0,2,3,4,6,8,9]
Output: ["0","2->4","6","8->9"]

問題解析：

給定一個遞增排序的數組，給出數組的範圍總結。

鏈接：

• https://leetcode.com/problems/summary-ranges/description/

解答：

• 問題不難，難點在於如何對數組的索引進行更新。

class Solution {
public:
    vector<string> summaryRanges(vector<int>& nums) {
        vector<string> ret;
        if(nums.size() == 0)
            return ret;

        for(int i=0; i<nums.size();){
            int start = i;
            int end = i;
            while(nums[end+1] == nums[end] + 1 && end < nums.size())
                end++;

            if(end == start){
                ret.push_back(to_string(nums[end]));
            }
            else{
                ret.push_back(to_string(nums[start]) + "->" + to_string(nums[end]));
            }   
            i = end + 1; 
        }

        return ret;
    }
};