942. DI String Match

A permutation perm of n + 1 integers of all the integers in the range [0, n] can be represented as a string s of length n where:

• s[i] == 'I' if perm[i] < perm[i + 1], and
• s[i] == 'D' if perm[i] > perm[i + 1].

Given a string s, reconstruct the permutation perm and return it. If there are multiple valid permutations perm, return any of them.

 

Example 1:

Input: s = "IDID"
Output: [0,4,1,3,2]

Example 2:

Input: s = "III"
Output: [0,1,2,3]

Example 3:

Input: s = "DDI"
Output: [3,2,0,1]

class Solution {
    public int[] diStringMatch(String S) {
        int n = S.length(), left = 0, right = n;
        int[] res = new int[n + 1];
        for (int i = 0; i < n; ++i)
            res[i] = S.charAt(i) == 'I' ? left++ : right--;
        res[n] = left;
        return res;
    }
}