Merge pull request #214 from bky373/main

[bky373] Week 14 Solutions

Author: leokim0922

set-matrix-zeroes/bky373.java

@@ -0,0 +1,29 @@
+// time: O(m*n)
+// space: O(m+n)
+class Solution {
+
+    public void setZeroes(int[][] matrix) {
+        int m = matrix.length;
+        int n = matrix[0].length;
+
+        int[] rows = new int[m];
+        int[] cols = new int[n];
+
+        for (int i = 0; i < m; i++) {
+            for (int j = 0; j < n; j++) {
+                if (matrix[i][j] == 0) {
+                    rows[i] = 1;
+                    cols[j] = 1;
+                }
+            }
+        }
+
+        for (int i = 0; i < m; i++) {
+            for (int j = 0; j < n; j++) {
+                if (rows[i] == 1 || cols[j] == 1) {
+                    matrix[i][j] = 0;
+                }
+            }
+        }
+    }
+}

spiral-matrix/bky373.java

@@ -0,0 +1,33 @@
+// time: O(m*n)
+// space: O(m*n)
+class Solution {
+
+    public List<Integer> spiralOrder(int[][] matrix) {
+        int m = matrix.length;
+        int n = matrix[0].length;
+        int dir = 1;
+        int i = 0;
+        int j = -1;
+
+        List<Integer> output = new ArrayList<>();
+
+        while (m * n > 0) {
+            for (int k = 0; k < n; k++) {
+                j += dir;
+                output.add(matrix[i][j]);
+            }
+
+            m--;
+
+            for (int k = 0; k < m; k++) {
+                i += dir;
+                output.add(matrix[i][j]);
+            }
+
+            n--;
+            dir *= -1;
+        }
+
+        return output;
+    }
+}

sum-of-two-integers/bky373.java

@@ -0,0 +1,15 @@
+// time: O(1)
+// space: O(1)
+class Solution {
+
+    public int getSum(int a, int b) {
+        while (b != 0) {
+            int ans = a ^ b;
+            int carry = (a & b) << 1;
+            a = ans;
+            b = carry;
+        }
+
+        return a;
+    }
+}