【LeetCode & 剑指offer 刷题笔记】目录（持续更新中...）
228. Summary Ranges
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.
/*
问题：有序数组总结范围（无重复数）
方法：扫描数组，用双指针找范围的左右端点
*/
class Solution
{
public:
vector<string> summaryRanges(vector<int>& nums)
{
vector<string> res;
if(nums.empty())
return res;
for(int i=0; i<nums.size();)
{
int left = i; //i=0~n-1
int right = i;
while( right+1 < nums.size() && nums[right+1] == nums[right] + 1 )
right++;
if(right == left)//范围等于1时
res.push_back(to_string(nums[right]));
else //范围大于1时
res.push_back(to_string(nums[left]) + "->" + to_string(nums[right]));
i = right + 1; //移动到当前范围的后一个元素
}
return res;
}
};