leetcode_summary_ranges

class Solution {
public:
    vector<string> summaryRanges(vector<int>& nums) {
        vector<string> ret;
        if (nums.size() == 0)   return ret;
        int start = nums[0];
        int end = nums[0];
        for(int i = 1; i < nums.size(); i++)
        {
            if(nums[i] == end+1)
            {
                end = end+1;
            }
            else
            {
                string s = (start != end)?(to_string(start)+"->"+to_string(end)):to_string(start);
                ret.push_back(s);
                start = nums[i];
                end = nums[i];
            }
        }
        string s = (start != end)?(to_string(start)+"->"+to_string(end)):to_string(start);
        ret.push_back(s);
        return ret;
    }
};