Maximum Gap

Given an unsorted array, find the maximum difference between the successive elements in its sorted form.

Try to solve it in linear time/space.

Return 0 if the array contains less than 2 elements.

You may assume all elements in the array are non-negative integers and fit in the 32-bit signed integer range.

Solution:

public class Solution {
    public int maximumGap(int[] nums) {
        if(nums.length<2) return 0;
        int max = Integer.MIN_VALUE;
        int min = Integer.MAX_VALUE;
        for(int n : nums){
            max = Math.max(max, n);
            min = Math.min(min, n);
        }
        int gap = (int)Math.ceil((double)(max-min)/(nums.length-1));
        if(gap==0) return 0;
        int[] maxArray = new int[nums.length];
        int[] minArray = new int[nums.length];
        Arrays.fill(minArray, Integer.MAX_VALUE);
        for(int n : nums){
            int i = (n-min)/gap;
            maxArray[i] = Math.max(maxArray[i], n);
            minArray[i] = Math.min(minArray[i], n);
        }
        int ans = 0;
        int pre = min;
        for(int i=0; i<nums.length; i++){
            if(minArray[i]==Integer.MAX_VALUE) continue;
            ans = Math.max(ans, minArray[i]-pre);
            pre = maxArray[i];
        }
        return ans;
    }
}