[알고리즘] Missing Ranges (java 풀이) leetcode

import java.util.ArrayList;
import java.util.List;

public class MissingRanges {

	public static void main(String[] args) {
		int[] nums = { 2, 3, 5, 50, 75 };
		int lower = 0, upper = 99;

		System.out.println(solve(nums, lower, upper));
	}

	public static List<String> solve(int[] nums, int lower, int upper) {

		ArrayList<String> list = new ArrayList<>();
		if (lower < nums[0]) {
			list.add(makeRange(lower, nums[0] - 1));
		}

		for (int i = 0; i < nums.length - 1; i++) {
			if (nums[i] + 1 != nums[i + 1]) {
				list.add(makeRange(nums[i] + 1, nums[i + 1] - 1));
			}

//			if(nums[i]+1 < nums[i+1] && nums[i]!=nums[i+1]) {
//				list.add(makeRange(nums[i]+1,nums[i+1]-1));
//			}
		}

		if (nums[nums.length - 1] < upper) {
			list.add(makeRange(nums[nums.length - 1] + 1, upper));
		}

		return list;

	}

	public static String makeRange(int low, int high) {
		return low == high ? String.valueOf(low) : (low + "->" + high);
	}

}

문제

Given a sorted integer array nums, where the range of elements are int the inclusive range [lower, upper], return its missing ranges.

 

exmple

		int[] nums = {2,3,5,50,75};
		int lower =0, upper =99;

result

[0->1, 4, 6->49, 51->74, 76->99]