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| 1 | +// https://leetcode.com/problems/insert-interval/submissions |
| 2 | +// T: O(n) |
| 3 | +// S: O(n) |
| 4 | + |
| 5 | +public class InsertInterval { |
| 6 | + public int[][] insert(int[][] intervals, int[] newInterval) { |
| 7 | + if (intervals.length == 0) return new int[][] {newInterval}; |
| 8 | + final int startIndex = search(intervals, newInterval[0]); |
| 9 | + final int endIndex = search(intervals, newInterval[1]); |
| 10 | + final int newStart = startIndex >= intervals.length |
| 11 | + ? newInterval[0] |
| 12 | + : Math.min(intervals[startIndex][0], newInterval[0]); |
| 13 | + final int newEnd = endIndex >= intervals.length |
| 14 | + ? newInterval[1] |
| 15 | + : newInterval[1] >= intervals[endIndex][0] ? intervals[endIndex][1] : newInterval[1]; |
| 16 | + final boolean hasMerged = hasMerged(intervals, newInterval, startIndex, endIndex); |
| 17 | + final int intervalMergedEnd = endIndex >= intervals.length |
| 18 | + ? intervals.length - 1 |
| 19 | + : newInterval[1] >= intervals[endIndex][0] ? endIndex : endIndex - 1; |
| 20 | + final int intervalMergedStart = startIndex; |
| 21 | + final int elements = intervals.length - (hasMerged ? intervalMergedEnd - intervalMergedStart : -1); |
| 22 | + final int[][] result = new int[elements][2]; |
| 23 | + int i = 0; |
| 24 | + for ( ; i < intervalMergedStart ; i++) result[i] = intervals[i]; |
| 25 | + result[i++] = new int[] {newStart, newEnd}; |
| 26 | + if (hasMerged) { |
| 27 | + for (i = intervalMergedEnd + 1 ; i < intervals.length ; i++) { |
| 28 | + result[i - (intervalMergedEnd - intervalMergedStart)] = intervals[i]; |
| 29 | + } |
| 30 | + } else { |
| 31 | + for ( ; i < intervals.length ; i++) { |
| 32 | + result[i] = intervals[i - 1]; |
| 33 | + } |
| 34 | + } |
| 35 | + return result; |
| 36 | + } |
| 37 | + |
| 38 | + private boolean hasMerged(int[][] intervals, int[] interval, int start, int end) { |
| 39 | + if (start >= intervals.length) return false; |
| 40 | + return interval[0] <= intervals[start][1] || |
| 41 | + (end < intervals.length && interval[1] >= intervals[end][0]); |
| 42 | + } |
| 43 | + |
| 44 | + private int search(int[][] array, int x) { |
| 45 | + int left = 0, right = array.length - 1, middle; |
| 46 | + while (left <= right) { |
| 47 | + middle = left + (right - left) / 2; |
| 48 | + if (array[middle][1] == x) return middle; |
| 49 | + else if (array[middle][1] > x) right = middle - 1; |
| 50 | + else left = middle + 1; |
| 51 | + } |
| 52 | + return left; |
| 53 | + } |
| 54 | +} |
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