Update 1632-rank-transform-of-a-matrix.js

Author: everthis

1632-rank-transform-of-a-matrix.js

@@ -88,3 +88,68 @@ function shakeRow(matrix, rowIndex, result) {
   }
   return changed
 }
+
+// another
+
+/**
+ * @param {number[][]} matrix
+ * @return {number[][]}
+ */
+const matrixRankTransform = function (matrix) {
+  const r = matrix.length,
+    c = matrix[0].length;
+  const t = r * c;
+  const arr = Array(t);
+  const root = Array(t + 1);
+  const rk = Array(t + 1).fill(0);
+  const find = (a) => {
+    let ra = root[a];
+    if (ra == a) return a;
+    return (root[a] = find(ra));
+  };
+  const union = (a, b) => {
+    let ra = find(a);
+    let rb = find(b);
+    if (ra !== rb) {
+      if (rk[ra] > rk[rb]) root[rb] = ra;
+      else root[ra] = rb;
+    }
+  };
+  let k = 0;
+  const ans = Array(r)
+    .fill(0)
+    .map(() => Array(c));
+  for (let i = 0; i < r; ++i) {
+    for (let j = 0; j < c; ++j) {
+      arr[k] = [matrix[i][j], i, j];
+      root[k] = k;
+      ++k;
+    }
+  }
+  root[k] = k;
+  arr.sort((a, b) => a[0] - b[0]);
+  const X = Array(r)
+    .fill(0)
+    .map(() => [-Infinity, t]);
+  const Y = Array(c)
+    .fill(0)
+    .map(() => [-Infinity, t]);
+  for (let i = 0; i < t; ++i) {
+    const [v, x, y] = arr[i];
+    const id = x * c + y;
+    const [xv, rx] = X[x],
+      [yv, ry] = Y[y];
+    if (v > xv) rk[id] = rk[find(rx)] + 1;
+    else root[id] = rx;
+    if (v > yv) rk[find(id)] = Math.max(rk[find(id)], rk[find(ry)] + 1);
+    else union(id, ry);
+    X[x] = [v, id];
+    Y[y] = [v, id];
+  }
+  for (let i = 0; i < r; ++i) {
+    for (let j = 0; j < c; ++j) {
+      ans[i][j] = rk[find(i * c + j)];
+    }
+  }
+  return ans;
+};