[LeetCode] 2451. Odd String Difference

2451-odd-string-difference.java

class Solution {
  
  private int[] calcDiff(char[] chars) {
    int[] diffs = new int[chars.length-1];
    for(int i = 0; i < chars.length - 1; i++) {
      diffs[i] = chars[i+1] - chars[i];
    }
    return diffs;
  }
  
  private boolean areArraysEq(int[] left, int[] right) {
    if (left.length != right.length) return false;
    for (int i = 0; i < left.length; i++) {
      if (left[i] != right[i]) {
        return false;
      }
    }
    return true;
  }
  
  // return index of odd: 0, 1, or 2, returns -1 otherwise
  private int vote(int[] prevDiff, int[] midDiff, int[] currDiff) {
    if (areArraysEq(prevDiff, midDiff) && areArraysEq(midDiff, currDiff)) {
      return -1;
    }
    if (areArraysEq(midDiff, currDiff)) {
      return 0;
    }
    if (areArraysEq(prevDiff, currDiff)) {
      return 1;
    }
    if (areArraysEq(prevDiff, midDiff)) {
      return 2;
    }
    return -1;
  }
  
  public String oddString(String[] words) {
    for(int i = 0; i < words.length - 2; i++) {
      int[] prevDiff = calcDiff(words[i].toCharArray());
      int[] midDiff = calcDiff(words[i + 1].toCharArray());
      int[] currDiff = calcDiff(words[i + 2].toCharArray());
      int voteIdx = vote(prevDiff, midDiff, currDiff);
      if (voteIdx != -1) {
        return words[voteIdx];
      } 
    }
    return "";
  }
}

class Scratch {
  public static void main(String[] args) {
    String[][] tcs = new String[3][];
    tcs[0] = new String[]{"adc","wzy","abc"};
    tcs[1] = new String[]{"aaa","bob","ccc","ddd"};
    tcs[2] = new String[]{"mll","edd","jii","tss","fee","dcc","nmm","abb","utt","zyy","xww","tss","wvv","xww","utt"};
    for (int i = 0; i < tcs.length; i++) {
      var sol = new Solution().oddString(tcs[i]);
      System.out.println(sol);
    }
  }
}