leetcode Weekly Contest 67 -- 763. Partition Labels

Description

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:
vector<int> partitionLabels(string S)
{
int len = 0,m=0;
vector<int>sum;
map<char,int>mp;
int i=0;

while (i<S.length())
{
len++;
for (; i < len; i++)
{
if (!mp.count(S[i]))
{
mp[S[i]] = 0;
for (int j = S.length() - 1; j >= i; j--)
{
if (S[i] == S[j])
{
if (len <= j)
len = j + 1;
break;
}
}
}
}
sum.push_back(len - m);
m = len;
}
return sum;
}
};