【刷题-LeetCode】228. Summary Ranges

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"]
Explanation: 0,1,2 form a continuous range; 4,5 form a continuous range.

Example 2:

Input:  [0,2,3,4,6,8,9]
Output: ["0","2->4","6","8->9"]
Explanation: 2,3,4 form a continuous range; 8,9 form a continuous range.

解 直接扫描

class Solution {
public:
    vector<string> summaryRanges(vector<int>& nums) {
        vector<string>ans;
        int start = 0;
        for(int i = 1; i <= nums.size(); ++i){
            if(i == nums.size() || nums[i] != nums[i-1] + 1){
                if(i == start+1){
                    ans.push_back(to_string(nums[start]));
                }else{
                    ans.push_back(to_string(nums[start])+"->"+to_string(nums[i-1]));
                }
                start = i;
            }
        }
        return ans;
    }
};