public static void main(String[] args) {

int[] array = {12, -5, 0, 23, -17, 8, -1, 34, -9, 2, 19, -12, 7, -3, 25, -20, 4, -7, 15, -2};

System.out.println(Arrays.toString(sort(array)));

}

static void swap(int[] arr , int first , int second){

int temp = arr[first];

arr[first] = arr[second];

arr[second] = temp;

}

static int getMaxIndex(int[] arr , int start , int end){

int max = start;

for (int i = start; i <= end ; i++) {

if(arr[max] < arr[i])

max = i;

}

return max;

}

static int[] sort(int[] arr){

for (int i = 0; i < arr.length; i++) {

int last = arr.length-i-1;

int maxIndex = getMaxIndex(arr , 0 , last);

swap(arr ,maxIndex , last);

}

return arr;

}