228. Summary Ranges

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

難度:

Medium

用一個head和headIdx來記錄當前consecutive的開始，一旦不再consecutive，push it in

然后應該可以把代碼寫的更簡單

class Solution(object):
    def summaryRanges(self, nums):
        """
        :type nums: List[int]
        :rtype: List[str]
        """
        if nums == []:
            return []
        tmp = []
        tmpl = []
    
    
        head = nums[0]
        headIdx = 0
    
        tmpl = [head]
    
        for i in range(1,len(nums)):
            #not consective anymore
            if nums[i] != head + i - headIdx :
                tmp.append(tmpl)
                head = nums[i]
                headIdx = i
                tmpl = []
                tmpl.append(head)
            #consective nums
            else:
                tmpl.append(nums[i])
        #push the last sequence in
        tmp.append(tmpl)

    
        res = []        
        for t in tmp:
            if len(t) == 1:
                res.append(str(t[0]))
            else:
                res.append(str(t[0])+"->" +str(t[-1]))
        return res