Create 1252-cells-with-odd-values-in-a-matrix.js

Author: everthis

1252-cells-with-odd-values-in-a-matrix.js

@@ -0,0 +1,31 @@
+/**
+ * @param {number} n
+ * @param {number} m
+ * @param {number[][]} indices
+ * @return {number}
+ */
+const oddCells = function (n, m, indices) {
+  const oddRows = new BitSet(n),
+    oddCols = new BitSet(m)
+  let cntRow = 0,
+    cntCol = 0
+  for (let idx of indices) {
+    oddRows.flip(idx[0])
+    oddCols.flip(idx[1])
+    cntRow += oddRows.get(idx[0]) ? 1 : -1
+    cntCol += oddCols.get(idx[1]) ? 1 : -1
+  }
+  return (m - cntCol) * cntRow + (n - cntRow) * cntCol
+}
+
+class BitSet {
+  constructor(n) {
+    this.arr = Array(n).fill(0)
+  }
+  flip(idx) {
+    this.arr[idx] = this.arr[idx] === 0 ? 1 : 0
+  }
+  get(idx) {
+    return this.arr[idx]
+  }
+}