LeetCode 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"]

Example 2:

Input: [0,2,3,4,6,8,9]Output: ["0","2->4","6","8->9"]

分析：

1.定义两个边界l,r。l为左边界，r为右边界，如果i位置与r位置相邻，将r设置为i；否则，重新设置左右边界，并将上一个存放

2.to_string():将数值转换为字符串

class Solution {public:    vector<string> summaryRanges(vector<int>& nums) {        string s;        vector<string>v;        if(nums.size()==0) return v;        int cnt=0,l=0,r=0;        for(int i=1;i<nums.size();i++){            if((nums[i]-nums[r])==1){                cnt++;                r=i;            }else{                s=to_string(nums[l]);                if(cnt>0) s+="->"+to_string(nums[r]);                v.push_back(s);                l=i;r=i;cnt=0;            }        }        s=to_string(nums[l]);        if(cnt>0) s=s+"->"+to_string(nums[r]);        v.push_back(s);                return v;    }};