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:
S
will have length in range[1, 500]
.S
will consist of lowercase letters ('a'
to'z'
) only.
class Solution { public List<Integer> partitionLabels(String S) { Map<Character, Integer> map = new HashMap<>(); for (int i = 0; i < S.length(); i++) { map.put(S.charAt(i), i); } int lastIndex = 0; int start = 0, i = 0; List<Integer> list = new ArrayList<>(); while (i < S.length()) { lastIndex = Math.max(lastIndex, map.get(S.charAt(i))); // current index get to farest up to now if (i == lastIndex) { list.add(lastIndex - start + 1); start = lastIndex + 1; } i += 1; } return list; } }