228_Summary_Ranges

Leetcode 228: Summary Ranges
Detailed video explanation: https://youtu.be/AjE4x3Yh9xc
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C++:
----
class Solution {
public:
    vector<string> summaryRanges(vector<int>& nums) {
        vector<string> result;
        int n = nums.size();
        if(n == 0) return result;
        int a = nums[0];
        for(int i = 0; i < n; ++i){
            if(i == n-1 || nums[i]+1 != nums[i+1]){
                if(nums[i] != a) result.push_back(to_string(a) + "->" + to_string(nums[i]));
                else result.push_back(to_string(a));
                if(i != n-1) a = nums[i+1];
            }
        }
        return result;
    }
};



Java:
-----
class Solution {
    public List<String> summaryRanges(int[] nums) {
        List<String> result = new ArrayList();
        int n = nums.length;
        if(n == 0) return result;
        int a = nums[0];
        for(int i = 0; i < n; ++i){
            if(i == n-1 || nums[i]+1 != nums[i+1]){
                if(nums[i] != a) result.add(a + "->" + nums[i]);
                else result.add(a + "");
                if(i != n-1) a = nums[i+1];
            }
        }
        return result;
    }
}



Python3:
-------
class Solution:
    def summaryRanges(self, nums: List[int]) -> List[str]:
        result, n = [], len(nums)
        if n == 0: return result
        a = nums[0]
        for i in range(n):
            if i == n-1 or nums[i]+1 != nums[i+1]:
                if nums[i] != a: result.append(str(a) + "->" + str(nums[i]))
                else: result.append(str(a))
                if i != n-1: a = nums[i+1]
        
        return result