763. Partition Labels

https://leetcode.com/problems/partition-labels/

Problem

A string S of lowercase English 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 English letters ('a' to 'z') only.

Solution

class Solution {
public:
    vector<int> partitionLabels(string S) {
        vector<int> partition;
        partition.reserve(S.size());
        int last_indice[26];
        for (int i = 0; i < S.size(); ++i) last_indice[S[i] - 'a'] = i;
        int count = 0, max_index = INT_MIN;
        for (int i = 0; i < S.size(); ++i) {
            if (last_indice[S[i] - 'a'] > max_index) max_index = last_indice[S[i] - 'a'];
            ++count;
            if (max_index == i) {
                partition.push_back(count);
                count = 0; max_index = INT_MIN;
            }
        }
        return partition;   
    }
};

• #string