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; auto start=nums.begin(); while(start != nums.end()) { auto end=start; end++; string tem=""; int x=*start; itos(tem,x); while(end != nums.end() && *end - *start == 1){ start++; end++; } if(x == *start) res.push_back(tem); else { tem+="->"; itos(tem,*start); res.push_back(tem); } start++; } return res; } void itos(string &str,int k) //主要是如何快速转换成字符串!!! { ostringstream oss;//创建一个流 oss<<k;//把值传递如流中 str+=oss.str(); } };