LeetCode/kt/shortest-distance-after-road-addition-queries-i.kt

class Solution {
    private fun findMinDistance(
        n: Int,
        graph: List<MutableList<Int>>,
    ): Int {
        val dp = IntArray(n)

        for (u in (0..n - 2).reversed()) {
            dp[u] = graph[u].minOfOrNull { v -> 1 + dp[v] } ?: n
        }

        return dp[0]
    }

    fun shortestDistanceAfterQueries(
        n: Int,
        queries: Array<IntArray>,
    ): IntArray {
        val distances = IntArray(queries.size)

        // Construct initial graph
        val graph = (1..n).map { mutableListOf(it) }.toList()
        graph.last().removeLast()

        // Process queries
        for (query in queries.withIndex()) {
            val (u, v) = query.value[0] to query.value[1]
            graph[u].add(v)

            distances[query.index] = findMinDistance(n, graph)
        }

        return distances
    }
}