Create 1722-minimize-hamming-distance-after-swap-operations.js

Author: everthis

1722-minimize-hamming-distance-after-swap-operations.js

@@ -0,0 +1,63 @@
+class UnionFind {
+  constructor(n) {
+    this.parents = Array(n)
+      .fill(0)
+      .map((e, i) => i)
+    this.ranks = Array(n).fill(0)
+  }
+  root(x) {
+    while (x !== this.parents[x]) {
+      this.parents[x] = this.parents[this.parents[x]]
+      x = this.parents[x]
+    }
+    return x
+  }
+  find(x) {
+    return this.root(x)
+  }
+  check(x, y) {
+    return this.root(x) === this.root(y)
+  }
+  union(x, y) {
+    const [rx, ry] = [this.find(x), this.find(y)]
+    if (this.ranks[rx] >= this.ranks[ry]) {
+      this.parents[ry] = rx
+      this.ranks[rx] += this.ranks[ry]
+    } else if (this.ranks[ry] > this.ranks[rx]) {
+      this.parents[rx] = ry
+      this.ranks[ry] += this.ranks[rx]
+    }
+  }
+}
+/**
+ * @param {number[]} source
+ * @param {number[]} target
+ * @param {number[][]} allowedSwaps
+ * @return {number}
+ */
+const minimumHammingDistance = function (source, target, allowedSwaps) {
+  let n = target.length
+  const u = new UnionFind(n)
+  for (let A of allowedSwaps) {
+    let i = A[0],
+      j = A[1]
+    u.union(i, j)
+  }
+  const M = {}
+  for (let i = 0; i < n; i++) {
+    let j = u.find(i)
+    if (M[j] == null) M[j] = {}
+    if (M[j][source[i]] == null) M[j][source[i]] = 0
+    M[j][source[i]]++
+  }
+  let rest = 0
+  for (let i = 0; i < n; i++) {
+    let j = u.find(i)
+    if (M[j][target[i]]) {
+      if (!--M[j][target[i]]) {
+        delete M[j][target[i]]
+      }
+    } else rest++
+  }
+  return rest
+}