LeetCode : 299. Bulls and Cows

[congr]

https://leetcode.com/problems/bulls-and-cows/

[congr]

O(N)

class Solution {
    public String getHint(String secret, String guess) {
        int[] s = new int[10];
        int[] g = new int[10];

        int bull = 0, cow = 0;
        for (int i = 0; i < secret.length(); i++) {
            int a = secret.charAt(i) - '0';
            int b = guess.charAt(i) - '0';

            if (a == b) bull++;
            else {
                s[a]++;
                g[b]++;
            }
        }

        for (int i = 0; i < 10; i++) cow += Math.min(s[i], g[i]);

        return bull + "A" + cow + "B";
    }
}