题目：

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"].

cpp：

class Solution {public:    vector
     
       summaryRanges(vector
      
       & nums) {        vector
       
         result;        if (nums.empty())            return result;        int start = nums[0];        int end = nums[0];        int len = nums.size();        for (int i = 1; i < len; i++) {            if ( nums[i] == nums[i - 1] || nums[i] == (nums[i-1]+1)) {                end = nums[i];            } else {                result.push_back(format(start,end));                start = nums[i];                end = start;            }        }        result.push_back(format(start,end));        return result;    }//    string format(int begin,int end){//        char buffer[32];//        if(begin == end){//            sprintf(buffer,"%d",begin);//        }else{//            sprintf(buffer,"%d->%d",begin,end);//        }//        return string(buffer);//    }        string format(int begin,int end){        stringstream ss;        if(begin == end){            ss << begin;        }else{            ss << begin << "->" << end;        }        return ss.str();    }};
       
      
     

python：

class Solution(object):    def summaryRanges(self, nums):        x, size = 0, len(nums);        result = []        while x < size:            c, r = x, str(nums[x])            while x + 1 < size and nums[x + 1] == nums[x] + 1:                x += 1            if x > c:                r += "->" + str(nums[x])            result.append(r)            x += 1        return result;