Given a positive integer n and a string s consisting only of letters D or I, you have to find any permutation of first n positive integer that satisfy the given input string.
D means the next number is smaller, while I means the next number is greater.
Notes
Length of given string s will always equal to n - 1
Your solution should run in linear time and space.
Example :
Input 1:
n = 3
s = ID
Return: [1, 3, 2]
思路:
每次看到I，从大到小fill结果。
Solution:
public class Solution {
// DO NOT MODIFY THE LIST. IT IS READ ONLY
public ArrayList<Integer> findPerm(final String A, int B) {
ArrayList<Integer> result = new ArrayList<>();
for (int i = 0; i <= A.length(); i ++) {
if (i == A.length() || A.charAt(i) == 'I') {
int size = result.size();
for (int j = i + 1; j > size; j --) {
result.add(j);
}
}
}
return result;
}
}