leetcode 228. Summary Ranges

/* leetcode 228. Summary Ranges 题目大意：对于给定的排序数组(无重复元素)，返回元素范围 譬如说：[0,1,2,4,5,7]，返回["0->2","4->5","7"] 解题思路： 1、确定范围：如果nums[end+1]==nums[end]+1,说明还是在一个返回 否则的话，就确定了一个返回。 2、格式输出：写一个函数按格式输出。 */

#include <iostream>
#include <vector>
#include <string>
using namespace std;

class Solution {
public:
    string format(int begin, int end)
    {
        char buffer[32];
        if (end == begin)
            sprintf(buffer, "%d", begin);
        else
            sprintf(buffer, "%d->%d", begin, end);

        return string(buffer);
    }
    vector<string> summaryRanges(vector<int>& nums) 
    {
        vector<string> result;
        if (nums.size() == 0)
            return result;
        int begin, end;
        begin = end= nums[0];
        for (int i = 1; i < nums.size(); ++i)
        {
            if (nums[i] == end + 1)
            {
                end = nums[i];
            }
            else
            {
                result.push_back(format(begin, end));
                begin = end = nums[i];
            }
        }

        result.push_back(format(begin, end));

        return result;

    }
};

void test_summaryRanges()
{
    Solution sol;
    vector<int> nums{0,1,2,4,5,7};
    vector<string> vecString = sol.summaryRanges(nums);
    for (auto s : vecString)
        cout << s << " ";
    cout << endl;
}

int main()
{
    test_summaryRanges();

    return 0;
}