763. Partition Labels(貪心)

標籤：res   一個   partition   無法   out   range   integer   for   oss   

A string S of lowercase letters is given. We want to partition this string into as many parts as possible so that each letter appears in at most one part, and return a list of integers representing the size of these parts.

Example 1:

Input: S = "ababcbacadefegdehijhklij"
Output: [9,7,8]
Explanation:
The partition is "ababcbaca", "defegde", "hijhklij".
This is a partition so that each letter appears in at most one part.
A partition like "ababcbacadefegde", "hijhklij" is incorrect, because it splits S into less parts.

Note:

1. S will have length in range [1, 500].
2. S will consist of lowercase letters (‘a‘ to ‘z‘) only.

class Solution:    def partitionLabels(self, S):        """        :type S: str        :rtype: List[int]        """        last = {} #記錄每一個字母出現的最後的位置        for  i in range(len(S)):            last[S[i]] = i        # print(last)        start,end = -1,0 #start是下一個欄位的首字母的前一個位置，第一個欄位的首字母的位置一定是0        res = []        for i in range(len(S)):            end = max(end,last[S[i]]) #不斷更新末尾指標的位置            if i==end: #當i指標的位置和末尾指標的位置相同時意味著[start,end]之間的字母的最後出現位置都在[start,end]，尾指標無法再更新                res.append(end-start) #當前欄位的長度                start = end #start是下一個欄位的首字母的前一個位置        return res

763. Partition Labels(貪心)