题目：

题解：

class Solution {
public:
    vector<string> summaryRanges(vector<int>& nums) {
        vector<string> ret;
        int i = 0;
        int n = nums.size();
        while (i < n) {
            int low = i;
            i++;
            while (i < n && nums[i] == nums[i - 1] + 1) {
                i++;
            }
            int high = i - 1;
            string temp = to_string(nums[low]);
            if (low < high) {
                temp.append("->");
                temp.append(to_string(nums[high]));
            }
            ret.push_back(move(temp));
        }
        return ret;
    }
};