Create 0399-evaluate-division.kt

Author: a93a

Diff for: kotlin/0399-evaluate-division.kt

@@ -0,0 +1,50 @@
+class Solution {
+    fun calcEquation(equations: List<List<String>>, values: DoubleArray, queries: List<List<String>>): DoubleArray {
+        val adj = HashMap<String, ArrayList<Pair<String, Double>>>().apply {
+            for (i in equations.indices) {
+                val (a, b) = equations[i]
+                val value = values[i]
+                this[a] = getOrDefault(a, arrayListOf()).apply { add(b to value) }
+                this[b] = getOrDefault(b, arrayListOf()).apply { add(a to (1.0 / value)) }
+            }
+        }
+
+        fun bfs(
+            start: String, 
+            end: String
+        ): Double {
+            if (start !in adj || end !in adj)
+                return -1.0
+            
+            val visit = HashSet<String>()
+            with (LinkedList<Pair<String, Double>>()) {
+                addLast(start to 1.0)
+                visit.add(start)
+
+                while (isNotEmpty()) {
+                    val (cur, totVal) = removeFirst()
+
+                    if (cur == end) return totVal
+
+                    adj[cur]?.forEach {
+                        val (next, nextVal) = it
+                        if (next !in visit) {
+                            addLast(next to (totVal * nextVal))
+                            visit.add(next)
+                        }
+                    }
+                }
+            }
+
+            return -1.0
+        }
+
+        val res = DoubleArray(queries.size)
+        for (i in queries.indices) {
+            val (a, b) =  queries[i]
+            res[i] = bfs(a, b)
+        }
+            
+        return res
+    }
+}