Missing Ranges

题目：

Given a sorted integer array where the range of elements are [0, 99] inclusive, return its
missing ranges.
For example, given [0, 1, 3, 50, 75], return [“2”, “4->49”, “51->74”, “76->99”]

 

解答：

public class Solution {

    public static void main(String[] args) {
        int[] arr = {0,1,3,50,75};
        int start = 0;
        int end = 99;
        
        List<String> results = findMissingRanges(arr, start, end);
    }

    public List<String> findMissingRanges(int[] vals, int start, int end) {
        List<String> ranges = new ArrayList<>();
        int prev = start - 1;
        for(int i = 0; i <= vals.length; i++) {
            int curr = (i == vals.length)?end+1:vals[i];
            if(curr - prev >= 2) {
                ranges.add(getRange(prev+1, curr-1));
            }

            prev = curr;
        }

        return ranges;
    }

    private String getRange(int from, int to) {
        return (from == to)?String.valueOf(from):from+"->" + to;
    }
}