leetcode-【中等题】228. Summary Ranges

题目：

228. Summary Ranges

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"].

答案：

就是找连续的序列。

直接判断相邻数据大小是否相差为1即可，主要是注意最后的数字要特殊考虑一下。

链接：

https://leetcode.com/problems/summary-ranges/

代码：

 #include <vector>

 #include <string>

 #include <sstream>

 using std::vector;

 using std::string;

 using std::ostringstream;

 class Solution {

 private:

     string num2str(int& num)

     {

         ostringstream stream;

         stream << num;

         return stream.str();

     }

 public:

     vector<string> summaryRanges(vector<int>& nums) {

         unsigned int len = nums.size();

         unsigned int index,inIndex;

         unsigned int minIndex = ;

         unsigned int maxIndex = ;

         vector<string> ans;

         if(len == )

         {

             return ans;

         }

         if(len == )

         {

             ans.push_back(num2str(nums[]));

             return ans;

         }

         for(index = ; index < len - ; ++ index)

         {

             if(nums[index] +  == nums[index + ])

             {

                 maxIndex = index + ;

             }else

             {

                 string tmp = "";

                 tmp += num2str(nums[minIndex]);

                 if(maxIndex > minIndex)

                 {

                     tmp += "->";

                     tmp += num2str(nums[maxIndex]);

                 }

                 ans.push_back(tmp);

                 minIndex = index + ;

                 maxIndex = index + ;

             }

         }

         if(nums[len-] +  == nums[len - ])

         {

             maxIndex = len - ;

         }else

         {

             minIndex = len - ;

             maxIndex = len - ;

         }

         string tmp = "";

         tmp += num2str(nums[minIndex]);

         if(maxIndex > minIndex)

         {

             tmp += "->";

             tmp += num2str(nums[maxIndex]);

         }

         ans.push_back(tmp);

         return ans;

     }

 };