set matrix zeroes solution

Author: hyer0705

set-matrix-zeroes/hyer0705.ts

@@ -0,0 +1,70 @@
+// mark first row, first col - 0ms
+/**
+ Do not return anything, modify matrix in-place instead.
+ */
+function setZeroes(matrix: number[][]): void {
+  const m = matrix.length;
+  const n = matrix[0].length;
+
+  let isFirstColZero = false;
+  let isFirstRowZero = false;
+  for (let i = 0; i < m; i++) {
+    for (let j = 0; j < n; j++) {
+      if (matrix[i][j] === 0) {
+        if (!isFirstRowZero && i === 0) isFirstRowZero = true;
+        if (!isFirstColZero && j === 0) isFirstColZero = true;
+        matrix[i][0] = 0;
+        matrix[0][j] = 0;
+      }
+    }
+  }
+
+  for (let i = 1; i < m; i++) {
+    for (let j = 1; j < n; j++) {
+      if (matrix[i][0] === 0 || matrix[0][j] === 0) {
+        matrix[i][j] = 0;
+      }
+    }
+  }
+
+  if (isFirstRowZero) {
+    for (let j = 0; j < n; j++) {
+      matrix[0][j] = 0;
+    }
+  }
+  if (isFirstColZero) {
+    for (let i = 0; i < m; i++) {
+      matrix[i][0] = 0;
+    }
+  }
+}
+
+// using set - 4ms
+/**
+ Do not return anything, modify matrix in-place instead.
+ */
+function setZeroes(matrix: number[][]): void {
+  const m = matrix.length;
+  const n = matrix[0].length;
+
+  // `${row},${col}`
+  const coordinates = new Set<string>();
+
+  for (let i = 0; i < m; i++) {
+    for (let j = 0; j < n; j++) {
+      if (matrix[i][j] === 0) {
+        coordinates.add(`${i},${j}`);
+      }
+    }
+  }
+
+  for (const coordinate of coordinates) {
+    const [x, y] = coordinate.split(",");
+    for (let j = 0; j < n; j++) {
+      matrix[x][j] = 0;
+    }
+    for (let i = 0; i < m; i++) {
+      matrix[i][y] = 0;
+    }
+  }
+}