How to get second highest element in unsorted int[] ? Please someone explain me with Java code :)

Answer 1

Why did you mention 'unsorted'? If you want second largest element, sort the array in ascending order and get second last element.

/* Sorting in Ascending order */
for (int i = 0; i < arr.length; i++) {
for (int j = i + 1; j < arr.length; j++) {
if (arr[i] > arr[j]) {
int temp = arr[i];
arr[i] = arr[j];
arr[j] = temp;
}
}
}

/* Getting second last element */
arr[arr.length - 2]

Answer 2

@Er. SANI : There's no direct way without sorting. But, you can find the largest number first and then find the largest number in the remaining array.

Answer 3

@krishna i don't want to sort array elements. is there any way to get second highest in unsorted array.

Answer 4

The safest way is to do comparison loop twice if you don't want to sort the array. If you want to do it in a single loop, you will get incorrect result when the first element is the biggest one.

int[] array = new int[]{9, 5, 6, 7, 8, 4, 2, 6, 1};
int max1, pos1, max2, pos2;
pos1 = -1;
max1 = Integer.MIN_VALUE;
for (int i=0; i<array.length; i++) {
if (array[i] > max1) {
// if you uncomment below and make a single loop
// you will get incorrect result
// pos2 = pos1;
// max2 = array[pos2];
pos1 = i;
max1 = array[pos1];
}
}
pos2 = -1;
max2 = Integer.MIN_VALUE;
for (int i=0; i<array.length; i++) {
if (i == pos1) continue; // skip the biggest one
if (array[i] > max2) {
pos2 = i;
max2 = array[pos2];
}
}
System.out.println("max2 = "+max2);