DI String Match.java

Ques:
Given a string S that only contains "I" (increase) or "D" (decrease), let N = S.length.

Return any permutation A of [0, 1, ..., N] such that for all i = 0, ..., N-1:

If S[i] == "I", then A[i] < A[i+1]
If S[i] == "D", then A[i] > A[i+1]
 

Example 1:

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

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

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

Note:

1 <= S.length <= 10000
S only contains characters "I" or "D".


Soln:
class Solution {
    public int[] diStringMatch(String S) {
        int high=S.length();
        int low=0;
        int ar[]=new int[high+1];
        for(int i=0;i<S.length();i++)
        {
         if(S.charAt(i)=='I')
             ar[i]=low++;
            else
                ar[i]=high--;
        
         
        }
        ar[S.length()]=high;
            return ar;
    }
}