leetcode-Summary Ranges

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

For example, given

[0,1,2,4,5,7]

, return

["0->2","4->5","7"].

class Solution {
public:
vector<string> summaryRanges(vector<int>& nums) {
vector<string> res;
if(nums.empty())
return res;
int begin=0,end;
int size=nums.size();

for(end=0;end<size;++end){
string temp(to_string(nums[begin]));
while(end+1<size&&nums[end]+1==nums[end+1])
++end;
if(begin!=end)
temp+="->"+to_string(nums[end]);
res.push_back(temp);
begin=end+1;
}
return res;
}
};