Given a stringS and a characterC, return an array of integers representing the shortest distance from the characterCin the string.

Example 1:

Input:
 S = "loveleetcode", C = 'e'

Output:
 [3, 2, 1, 0, 1, 0, 0, 1, 2, 2, 1, 0]

Note:

1. S string length is in [1, 10000].
2. C is a single character, and guaranteed to be in string S .
3. All letters in S and C are lowercase.

class Solution {
    public int[] shortestToChar(String S, char C) {
        int N = S.length();
        int[] ans = new int[N];
        int prev = -10000;

        for (int i = 0; i < N; ++i) {
            if (S.charAt(i) == C) prev = i;
            ans[i] = i - prev;
        }

        prev = 10000;
        for (int i = N-1; i >= 0; --i) {
            if (S.charAt(i) == C) prev = i;
            ans[i] = Math.min(ans[i], prev - i);
        }

        return ans;
    }
}