436. Find Right Interval

You are given an array of intervals, where intervals[i] = [starti, endi] and each starti is unique.

The r ight ** interval** for an interval i is an interval j such that startj>= endi and startj is minimized.

Return an array of right interval indices for each interval i. If no right interval exists for interval i, then put -1 at index i.

Example 1:

Input: intervals = [[1,2]]
Output: [-1]
Explanation: There is only one interval in the collection, so it outputs -1.

Example 2:

Input: intervals = [[3,4],[2,3],[1,2]]
Output: [-1,0,1]
Explanation: There is no right interval for [3,4].
The right interval for [2,3] is [3,4] since start0 = 3 is the smallest start that is >= end1 = 3.
The right interval for [1,2] is [2,3] since start1 = 2 is the smallest start that is >= end2 = 2.

Example 3:

Input: intervals = [[1,4],[2,3],[3,4]]
Output: [-1,2,-1]
Explanation: There is no right interval for [1,4] and [3,4].
The right interval for [2,3] is [3,4] since start2 = 3 is the smallest start that is >= end1 = 3.

Constraints:

• 1 <= intervals.length <= 2 * 104
• intervals[i].length == 2
• -106 <= starti <= endi <= 106
• The start point of each interval is unique.

# @lc code=start
using LeetCode

function find_right_interval(intervals::Vector{Tuple{Int,Int}})
    perm = sortperm(intervals; by = x -> x[1])
    maxb = intervals[perm[end]][1]
    res = fill(0, length(intervals))
    for (idx, intv) in intervals |> enumerate
        res[idx] = intv[2] > maxb ? -1 : searchsortedfirst(perm, intv[2]; by = i -> intervals[i][1])
    end
    return res
end
# @lc code=end

find_right_interval (generic function with 1 method)

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