complete 11760.kt 20955.kt

storage/zeta/kt/completed/20955.kt

@@ -0,0 +1,39 @@
+fun find(parents: IntArray, x: Int): Int {
+    var node = x
+    while (parents[node] != node) {
+        node = parents[node]
+    }
+    return node
+}
+
+fun union(parents: IntArray, a: Int, b: Int): Boolean {
+    val ra = find(parents, a)
+    val rb = find(parents, b)
+    if (ra == rb) return false
+    if (ra > rb) parents[rb] = ra else parents[ra] = rb
+    return true
+}
+
+fun minimumOperations(n: Int, edges: List<Pair<Int, Int>>): Int {
+    val parents = IntArray(n) { it }
+    var operations = 0
+    edges.forEach { (a, b) ->
+        if (!union(parents, a, b)) {
+            operations++
+        }
+    }
+
+    val rooted_parents = parents.map { find(parents, it) }
+    operations += rooted_parents.distinct().size - 1
+    return operations
+}
+
+
+fun main() = with(System.`in`.bufferedReader()) {
+    val (n, m) = this.readLine().split(" ").map { it.toInt() }
+    val synapses: List<Pair<Int, Int>> = (1..m).map {
+        this.readLine().split(" ").map { it.toInt() - 1 }.let { (a, b) -> a to b }
+    }
+
+    println(minimumOperations(n, synapses))
+}