non-overlapping-intervals

https://leetcode.com/problems/non-overlapping-intervals/

其中还用到了Java的Comparator接口和其中的compare方法。

package com.company;

import java.util.*;

class Interval {
        int start;
        int end;
        Interval() { start = 0; end = 0; }
        Interval(int s, int e) { start = s; end = e; }
}


class Solution {
    class IntervalComp implements Comparator {

        @Override
        public int compare(Object o1, Object o2) {
            Interval i1 = (Interval)o1;
            Interval i2 = (Interval)o2;
            return i1.start - i2.start;
        }
    }

    public int eraseOverlapIntervals(Interval[] intervals) {
        if (intervals.length == 0) {
            return 0;
        }

        Arrays.sort(intervals, new IntervalComp());

        int ret = 0;
        int last = intervals[0].end;
        for (int i=1; i<intervals.length; i++) {
            if (intervals[i].start >= last) {
                last = intervals[i].end;
                continue;
            }
            if (intervals[i].end >= last) {
                ret++;
            }
            else {
                ret++;
                last = intervals[i].end;
            }
        }
        return ret;
    }
}

public class Main {

    public static void main(String[] args) throws InterruptedException {

        System.out.println("Hello!");
        Solution solution = new Solution();

        Interval[] it = new Interval[2];
        it[0] = new Interval(1, 2);
        it[1] = new Interval(2, 3);
        int ret = solution.eraseOverlapIntervals(it);
        System.out.printf("Get ret: %d
", ret);
        System.out.println();

        /*Iterator<List<Integer>> iterator = ret.iterator();
        while (iterator.hasNext()) {
            Iterator iter = iterator.next().iterator();
            while (iter.hasNext()) {
                System.out.printf("%d,", iter.next());
            }
            System.out.println();
        }*/

        System.out.println();

    }
}