Evan Week 14

set-matrix-zeroes/evan.py

@@ -0,0 +1,37 @@
+from typing import List
+
+
+class Solution:
+    def setZeroes(self, matrix: List[List[int]]) -> None:
+        """
+        Do not return anything, modify matrix in-place instead.
+        """
+        if not matrix or not matrix[0]:
+            return
+
+        rows, cols = len(matrix), len(matrix[0])
+        first_row_has_zero = any(matrix[0][j] == 0 for j in range(cols))
+        first_col_has_zero = any(matrix[i][0] == 0 for i in range(rows))
+
+        # Use the first row and first column to mark zeros
+        for i in range(1, rows):
+            for j in range(1, cols):
+                if matrix[i][j] == 0:
+                    matrix[0][j] = 0
+                    matrix[i][0] = 0
+
+        # Set matrix elements to zero based on marks
+        for i in range(1, rows):
+            for j in range(1, cols):
+                if matrix[0][j] == 0 or matrix[i][0] == 0:
+                    matrix[i][j] = 0
+
+        # Set the first row to zero if needed
+        if first_row_has_zero:
+            for j in range(cols):
+                matrix[0][j] = 0
+
+        # Set the first column to zero if needed
+        if first_col_has_zero:
+            for i in range(rows):
+                matrix[i][0] = 0

spiral-matrix/evan.py

@@ -0,0 +1,40 @@
+from typing import List
+
+
+class Solution:
+    def spiralOrder(self, matrix: List[List[int]]) -> List[int]:
+        if not matrix or not matrix[0]:
+            return []
+
+        result = []
+        left, right = 0, len(matrix[0]) - 1
+        top, bottom = 0, len(matrix) - 1
+
+        while left <= right and top <= bottom:
+            # Traverse from left to right
+            for i in range(left, right + 1):
+                result.append(matrix[top][i])
+            # Move the top boundary down
+            top += 1
+
+            # Traverse from top to bottom
+            for i in range(top, bottom + 1):
+                result.append(matrix[i][right])
+            # Move the right boundary to the left
+            right -= 1
+
+            if top <= bottom:
+                # Traverse from right to left
+                for i in range(right, left - 1, -1):
+                    result.append(matrix[bottom][i])
+                # Move the bottom boundary up
+                bottom -= 1
+
+            if left <= right:
+                # Traverse from bottom to top
+                for i in range(bottom, top - 1, -1):
+                    result.append(matrix[i][left])
+                # Move the left boundary to the right
+                left += 1
+
+        return result

sum-of-two-integers/evan.py

@@ -0,0 +1,23 @@
+class Solution:
+    def getSum(self, a: int, b: int) -> int:
+        # 32비트 마스크
+        MASK = 0xFFFFFFFF
+        # 최대 32비트 정수 값
+        MAX_INT = 0x7FFFFFFF
+
+        while b != 0:
+            # a와 b의 XOR (덧셈 결과)
+            a_xor_b = (a ^ b) & MASK
+            # 자리 올림 (AND 연산 후 한 비트 왼쪽 시프트)
+            carry = ((a & b) << 1) & MASK
+
+            # a를 XOR 결과로 업데이트
+            a = a_xor_b
+            # b를 자리 올림 값으로 업데이트
+            b = carry
+
+        if a > MAX_INT:
+            # 음수 처리
+            a = ~(a ^ MASK)
+
+        return a