?LeetCode刷題實(shí)戰(zhàn)228：匯總區(qū)間

示例 1：

輸入：nums = [0,1,2,4,5,7]
輸出：["0->2","4->5","7"]
解釋：區(qū)間范圍是：
[0,2] --> "0->2"
[4,5] --> "4->5"
[7,7] --> "7"

示例 2：

輸入：nums = [0,2,3,4,6,8,9]
輸出：["0","2->4","6","8->9"]
解釋：區(qū)間范圍是：
[0,0] --> "0"
[2,4] --> "2->4"
[6,6] --> "6"
[8,9] --> "8->9"

示例 3：

輸入：nums = []
輸出：[]

示例 4：

輸入：nums = [-1]
輸出：["-1"]

示例 5：

輸入：nums = [0]
輸出：["0"]

class Solution {
public:
    vector<string> summaryRanges(vector<int>& nums) {
        vector<string> r;
        if(nums.size()==0) return r;
        int a = nums[0];
        int c = nums[0];
        bool b = true;
        for(int i= 1;i<nums.size();i++)
        {
            if(c+1 == nums[i])
            {
                c = nums[i];
            }
            else
            {
                if(b){
                    if(c == a)
                    {
                        r.push_back(to_string(a));
                        b = false;
                        i--;
                    }
                    else
                    {
                        r.push_back(to_string(a)+"->"+to_string(c));
                        b = false;
                        i--;
                    }
                }
                else{
                    a = nums[i];
                    c = nums[i];
                    b = true;
                }
            }
        }
        if(b){
            if(c == a)
            {
                r.push_back(to_string(a));
                b = false;
            }
            else
            {
                r.push_back(to_string(a)+"->"+to_string(c));
            }
        }
        return r;
    }
};