Update 2322-minimum-score-after-removals-on-a-tree.js

Author: everthis

2322-minimum-score-after-removals-on-a-tree.js

@@ -1,3 +1,84 @@
+/**
+ * @param {number[]} nums
+ * @param {number[][]} edges
+ * @return {number}
+ */
+const minimumScore = function (nums, edges) {
+  const n = nums.length, m = edges.length
+  const graph = {}
+  const children = {}
+  const xor = nums.slice(0)
+  const degree = Array(n).fill(0)
+
+  for(const [p, q] of edges) {
+    if(graph[p] == null) graph[p] = []
+    if(graph[q] == null) graph[q] = []
+    graph[p].push(q)
+    graph[q].push(p)
+    degree[p]++
+    degree[q]++
+  }
+
+  let val = 0
+  const seen = new Set()
+  const queue = []
+  for(let i = 0; i < n; i++) {
+    val ^= nums[i]
+    if(degree[i] === 1) {
+      queue.push(i)
+      seen.add(i)
+    }
+  }
+
+  while(queue.length) {
+    const cur = queue.shift()
+    for(const nxt of (graph[cur] || [])) {
+      if(!seen.has(nxt)) {
+        if(children[nxt] == null) children[nxt] = new Set()
+        children[nxt].add(cur)
+        for(const e of (children[cur] || [])) {
+          children[nxt].add(e)
+        }
+        xor[nxt] ^= xor[cur]
+      }
+      degree[nxt]--
+      if(degree[nxt] === 1) {
+        seen.add(nxt)
+        queue.push(nxt)
+      }
+    }
+  }
+
+  let res = Infinity
+
+  for(let i = 0; i < m - 1; i++) {
+    for(let j = i + 1; j < m; j++) {
+      let [a, b] = edges[i]
+      // Let a, c be the lower break points
+      if(children[a]?.has(b)) {
+        ;[a, b] = [b, a]
+      }
+      let [c, d] = edges[j]
+      if(children[c]?.has(d)) {
+        ;[c, d] = [d, c]
+      } 
+      let cur
+      if(children[a]?.has(c)) {
+        cur = [xor[c], xor[a] ^ xor[c], val ^ xor[a]] 
+      } else if(children[c]?.has(a)) {
+        cur = [xor[a], xor[c] ^ xor[a], val ^ xor[c]]
+      } else {
+        cur = [xor[a], xor[c], val ^ xor[a] ^ xor[c]]
+      }
+      res = Math.min(res, Math.max(...cur) - Math.min(...cur))
+    }
+  }
+
+  return res
+}
+
+// another
+
 /**
  * @param {number[]} nums
  * @param {number[][]} edges