Create 924-minimize-malware-spread.js

Author: everthis

924-minimize-malware-spread.js

@@ -0,0 +1,63 @@
+/**
+ * @param {number[][]} graph
+ * @param {number[]} initial
+ * @return {number}
+ */
+const minMalwareSpread = function (graph, initial) {
+  const l = graph.length
+  const p = []
+  const children = []
+  for (let i = 0; i < l; i++) {
+    p[i] = i
+    children[i] = [i]
+  }
+
+  for (let i = 0; i < l; i++) {
+    for (let j = i + 1; j < l; j++) {
+      if (graph[i][j] === 1) {
+        const pi = find(i)
+        const pj = find(j)
+        if (pi !== pj) {
+          union(pi, pj)
+        }
+      }
+    }
+  }
+
+  initial.sort((a, b) => (a > b ? 1 : -1))
+
+  const count = {}
+
+  let index = initial[0]
+  let max = 0
+  // find the index that not unioned with other indexes and with the most number of children
+  initial.forEach((e) => {
+    const pe = find(e)
+    if (!count[pe]) count[pe] = 0
+    count[pe] += 1
+  })
+  initial.forEach((e, i) => {
+    const pe = find(e)
+    if (count[pe] === 1 && children[pe].length > max) {
+      max = children[pe].length
+      index = e
+    }
+  })
+
+  return index
+
+  function find(x) {
+    while (p[x] !== x) {
+      p[x] = p[p[x]]
+      x = p[x]
+    }
+    return x
+  }
+
+  function union(pi, pj) {
+    p[pj] = pi
+    //also move the children to the new parent
+    children[pi] = children[pi].concat(children[pj])
+    children[pj] = []
+  }
+}