Completed s30 Array-1

diagonal.py

@@ -0,0 +1,39 @@
+class Solution:
+    def findDiagonalOrder(self, mat):
+        m, n = len(mat), len(mat[0])
+        result = [0] * (m * n)
+        r = c = 0
+        dir = True
+
+        for i in range(m * n):
+            result[i] = mat[r][c]
+
+            if dir:
+                if c == n - 1:
+                    r += 1
+                    dir = False
+                elif r == 0:
+                    c += 1
+                    dir = False
+                else:
+                    r -= 1
+                    c += 1
+            else:
+                if r == m - 1:
+                    c += 1
+                    dir = True
+                elif c == 0:
+                    r += 1
+                    dir = True
+                else:
+                    r += 1
+                    c -= 1
+
+        return result
+
+mat = [[1,2],[3,4]]
+s = Solution()
+print(s.findDiagonalOrder(mat))
+
+# TC - O(m*n)
+# SC - O(1)

prodofarrexceptself.py

@@ -0,0 +1,28 @@
+class Solution:
+    def productExceptSelf(self, nums):
+        n = len(nums)
+        result = [0] * n
+
+        rp = 1
+        result[0] = 1
+
+        for i in range(1, n):  # left pass
+            rp = rp * nums[i - 1]
+            result[i] = rp
+
+        #print(result)
+        rp = 1
+
+        for i in range(n - 2, -1, -1):  # right pass
+            rp = rp * nums[i + 1]
+            # print(rp)
+            result[i] = result[i] * rp
+
+        return result
+
+nums = [1,2,3,4]
+s = Solution()
+print(s.productExceptSelf(nums))
+
+# TC  - O(n)
+# SC - O(1) auxiliary space

spiral.py

@@ -0,0 +1,41 @@
+class Solution:
+    def spiralOrder(self, matrix):
+        m = len(matrix)
+        n = len(matrix[0])
+        result = []
+
+        r, c = 0, 0
+
+        for _ in range(m * n):
+            while c < n and matrix[r][c] != float('-inf'):
+                result.append(matrix[r][c])
+                matrix[r][c] = float('-inf')
+                c += 1
+            c -= 1; r += 1
+
+            while r < m and matrix[r][c] != float('-inf'):
+                result.append(matrix[r][c])
+                matrix[r][c] = float('-inf')
+                r += 1
+            r -= 1; c -= 1
+
+            while c >= 0 and matrix[r][c] != float('-inf'):
+                result.append(matrix[r][c])
+                matrix[r][c] = float('-inf')
+                c -= 1
+            c += 1; r -= 1
+
+            while r >= 0 and matrix[r][c] != float('-inf'):
+                result.append(matrix[r][c])
+                matrix[r][c] = float('-inf')
+                r -= 1
+            r += 1; c += 1
+
+        return result
+
+matrix = [[1,2,3],[4,5,6],[7,8,9]]
+s = Solution()
+print(s.spiralOrder(matrix))
+
+# TC = O(m*n)
+# SC = O(1)