Given a sorted integer array without duplicates, return the summary of its ranges.
Example 1:
Input: [0,1,2,4,5,7] Output: ["0->2","4->5","7"] Explanation: 0,1,2 form a continuous range; 4,5 form a continuous range.
Example 2:
Input: [0,2,3,4,6,8,9] Output: ["0","2->4","6","8->9"] Explanation: 2,3,4 form a continuous range; 8,9 form a continuous range.
思路不难，从头到尾，从头到尾数数字，然后看是否连续就行， 这个答案是我在高票回答的评论中找到的，感觉写的通俗易懂，非常棒！
https://leetcode.com/problems/summary-ranges/discuss/63284/10-line-c%2B%2B-easy-understand
1 vector<string> summaryRanges(vector<int>& nums) { 2 vector<string> res; 3 4 for (int i = 0, n = nums.size(); i < n; i++) { 5 int begin = nums[i]; 6 while (i != (n - 1) && nums[i] == nums[i + 1] - 1) 7 i++; 8 int end = nums[i]; 9 if (begin == end) 10 res.push_back(to_string(begin)); 11 else 12 res.push_back(to_string(begin) + "->" + to_string(nums[i])); 13 } 14 15 return res; 16 }