Algorithm_Collection/leetcode_java/T164_maximum_gap.java at master · dotastar/Algorithm_Collection

41 lines (41 loc) · 1.56 KB

public class Solution {
public int maximumGap(int[] num) {
    if (num == null || num.length < 2)
        return 0;
    // get the max and min value of the array
    int min = num[0];
    int max = num[0];
    for (int i:num) {
        min = Math.min(min, i);
        max = Math.max(max, i);
    }
    // the minimum possibale gap, ceiling of the integer division
    int gap = (int)Math.ceil((double)(max - min)/(num.length - 1));
    int[] bucketsMIN = new int[num.length - 1]; // store the min value in that bucket
    int[] bucketsMAX = new int[num.length - 1]; // store the max value in that bucket
    Arrays.fill(bucketsMIN, Integer.MAX_VALUE);
    Arrays.fill(bucketsMAX, Integer.MIN_VALUE);
    // put numbers into buckets
    for (int i:num) {
        if (i == min || i == max)
            continue;
        int idx = (i - min) / gap; // index of the right position in the buckets
        bucketsMIN[idx] = Math.min(i, bucketsMIN[idx]);
        bucketsMAX[idx] = Math.max(i, bucketsMAX[idx]);
    }
    // scan the buckets for the max gap
    int maxGap = Integer.MIN_VALUE;
    int previous = min;
    for (int i = 0; i < num.length - 1; i++) {
        if (bucketsMIN[i] == Integer.MAX_VALUE && bucketsMAX[i] == Integer.MIN_VALUE)
            // empty bucket
            continue;
        // min value minus the previous value is the current gap
        maxGap = Math.max(maxGap, bucketsMIN[i] - previous);
        // update previous bucket value
        previous = bucketsMAX[i];
    }
    maxGap = Math.max(maxGap, max - previous); // updata the final max value gap
    return maxGap;
}
}

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Expand file tree

Search code, repositories, users, issues, pull requests...

Uh oh!

FilesExpand file tree

T164_maximum_gap.java

Latest commit

History

T164_maximum_gap.java

File metadata and controls

Expand file tree