1 class Solution { 2 public: 3     vector<string> summaryRanges(vector<int>& nums) { 4         vector<string> v; 5         int len=nums.size(); 6         if(len==0) return v; 7         int low=nums[0]; 8         if(len==1){ 9             char a[20];10             sprintf(a,"%d",low);11             string s=a;12             v.push_back(s);13             return v;14         }15         int high;16         for(int i=1;i<len;i++){17             if(nums[i]==nums[i-1]+1) continue;18             high=nums[i-1];19             char a[20];20             sprintf(a,"%d",low);21             string s=a;22             if(low!=high){23                 s+="->";24                 char b[20];25                 sprintf(b,"%d",high);26                 s+=b;    27             } 28             v.push_back(s);29             low=nums[i];30         }31         high=nums[len-1];32         char a[20];33         sprintf(a,"%d",low);34         string s=a;35         if(low!=high){36             s+="->";37             char b[20];38             sprintf(b,"%d",high);39             s+=b;    40         } 41         v.push_back(s);42         return v;43     }44 };