Programming Test - Codility - Dominator [closed]

Answer 1

How about sorting the array first? You then compare middle and first and last elements of the sorted array to find the dominant element.

public Integer findDominator(int[] arr) {
    int[] arrCopy = arr.clone();

    Arrays.sort(arrCopy);

    int length = arrCopy.length;
    int middleIndx = (length - 1) /2;

    int middleIdxRight;
    int middleIdxLeft = middleIndx;

    if (length % 2 == 0) {
        middleIdxRight = middleIndx+1;
    } else {
        middleIdxRight = middleIndx;
    }

    if (arrCopy[0] == arrCopy[middleIdxRight]) {
        return arrCopy[0];
    }

    if (arrCopy[middleIdxLeft] == arrCopy[length -1]) {
        return arrCopy[middleIdxLeft];
    }

    return null;
}