Solution #73 - Jabez/Edited - 17/3/2025

Arrays101/#73-Set Matrix Zeroes-Medium/Set Matrix Zeroes - Explanation.md

@@ -0,0 +1,29 @@
+What This Code Does:
+* Find zeros in the matrix
+
+* If a cell is 0, mark its row and column to be zero later.
+* Use the first row & column as markers
+
+* To track if first row and column have zeros we use firstrow and firstcol boolean variables 
+
+* Instead of creating extra memory, the first row and column store which rows/columns should be zero.
+* Set the marked cells to zero
+
+* Go through the matrix and make elements 0 based on the markers.
+* Handle the first row and column separately
+
+If the first row/column originally had a 0, set the entire first row/column to 0.
+
+Imagine this matrix:
+
+
+1   2   3
+4   0   6
+7   8   9
+
+After running the code, it becomes:
+
+1   0   3
+0   0   0
+7   0   9
+The 0 at (1,1) caused its entire row and column to be zero.

Arrays101/#73-Set Matrix Zeroes-Medium/Set Matrix Zeroes - Solution.java

@@ -0,0 +1,42 @@
+class Solution{
+    public void SetMatrixZeroes(int[][] matrix) {
+        boolean firstrow = false, firstcol = false; // Used to check if the first row and first column contain any zeros
+
+        // Iterate through the matrix to find zeros
+        for (int i = 0; i < matrix.length; i++) {
+            for (int j = 0; j < matrix[0].length; j++) {
+                if (matrix[i][j] == 0) { // If an element is 0, mark its row and column in the first row and first column
+                    if (i == 0) firstrow = true; // Mark that the first row has a zero
+                    if (j == 0) firstcol = true; // Mark that the first column has a zero
+
+                    // Store zero markers in the first row and first column
+                    matrix[i][0] = 0;
+                    matrix[0][j] = 0;
+                }
+            }
+        }
+
+        // Use the markers in the first row and column to set matrix elements to zero
+        for (int i = 1; i < matrix.length; i++) {
+            for (int j = 1; j < matrix[0].length; j++) {
+                if (matrix[i][0] == 0 || matrix[0][j] == 0) {
+                    matrix[i][j] = 0;
+                }
+            }
+        }
+
+        // If the first row was marked, set all elements in the first row to zero
+        if (firstrow) {
+            for (int j = 0; j < matrix[0].length; j++) {
+                matrix[0][j] = 0;
+            }
+        }
+
+        // If the first column was marked, set all elements in the first column to zero
+        if (firstcol) {
+            for (int i = 0; i < matrix.length; i++) {
+                matrix[i][0] = 0;
+            }
+        }
+    }
+}