_436.java

package com.fishercoder.solutions;

import com.fishercoder.common.classes.Interval;

import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

public class _436 {

    public static class Solution1 {
        public int[] findRightInterval(Interval[] intervals) {
            if (intervals == null || intervals.length == 0) {
                return new int[0];
            }
            int[] result = new int[intervals.length];
            result[0] = -1;
            Interval last = intervals[intervals.length - 1];
            Interval first = intervals[0];
            Map<Interval, Integer> map = new HashMap();
            for (int i = 0; i < intervals.length; i++) {
                map.put(intervals[i], i);
            }

            Collections.sort(Arrays.asList(intervals), (o1, o2) -> o1.start - o2.start);

            for (int i = 1; i < intervals.length; i++) {
                //TODO: use binary search for the minimum start interval for interval[i-1] instead of a while loop
                int tmp = i - 1;
                int tmpI = i;
                while (tmpI < intervals.length && intervals[tmpI].start < intervals[tmp].end) {
                    tmpI++;
                }
                if (tmpI < intervals.length) {
                    result[map.get(intervals[tmp])] = map.get(intervals[tmpI]);
                } else {
                    result[map.get(intervals[tmp])] = -1;
                }
            }
            if (result[intervals.length - 1] == 0 && last.end > first.start) {
                result[intervals.length - 1] = -1;
            }
            return result;
        }
    }

}