"Set Matrix Zeroes"

Author: lennylxx

src/73.c

@@ -0,0 +1,59 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+/* space: O(m+n) */
+void setZeroes(int **matrix, int m, int n) {
+    int *row_flag = (int *)calloc(m, sizeof(int));
+    int *col_flag = (int *)calloc(n, sizeof(int));
+
+    int i, j, ii, jj;
+    for (i = 0; i < m; i++) {
+        for (j = 0; j < n; j++) {
+            if (matrix[i][j] == 0) {
+                row_flag[i] = 1;
+                col_flag[j] = 1;
+            }
+        }
+    }
+    for (j = 0; j < n; j++) {
+        if (col_flag[j]) {
+            for (ii = 0; ii < m; ii++) {
+                matrix[ii][j] = 0;
+            }
+        }
+    }
+    for (i = 0; i < m; i++) {
+        if (row_flag[i]) {
+            for (jj = 0; jj < n; jj++) {
+                matrix[i][jj] = 0;
+            }
+        }
+    }
+}
+
+int main() {
+    int m, n, i, j;
+    m = 5;
+    n = 4;
+
+    int **matrix = (int **)calloc(m, sizeof(int *));
+    for (i = 0; i < m; i++)
+        matrix[i] = (int *)calloc(n, sizeof(int));
+
+    matrix[0][0] = 0; matrix[0][1] = 0; matrix[0][2] = 0; matrix[0][3] = 5;
+    matrix[1][0] = 4; matrix[1][1] = 3; matrix[1][2] = 1; matrix[1][3] = 4;
+    matrix[2][0] = 0; matrix[2][1] = 1; matrix[2][2] = 1; matrix[2][3] = 4;
+    matrix[3][0] = 1; matrix[3][1] = 2; matrix[3][2] = 1; matrix[3][3] = 3;
+    matrix[4][0] = 0; matrix[4][1] = 0; matrix[4][2] = 1; matrix[4][3] = 1;
+
+    setZeroes(matrix, m, n);
+
+    for (i = 0; i < m; i++) {
+        for (j = 0; j < n; j++) {
+            printf("%d ", matrix[i][j]);
+        }
+        printf("\n");
+    }
+
+    return 0;
+}