solves 64: Minimum Path Sum

Author: sumanth-botlagunta

python/minimum_path_sum.py

@@ -0,0 +1,19 @@
+# https://leetcode.com/problems/minimum-path-sum/
+# T: O(m*n) where n is the number of rows and m is the number of columns
+# S: O(1) 
+
+class Solution:
+    def minPathSum(self, grid):
+      rows,  columns = len(grid), len(grid[0])
+
+      for column in range(columns - 2, -1, -1):
+          grid[rows - 1][column] += grid[rows - 1][column + 1]
+
+      for row in range(rows - 2, -1, -1):
+          grid[row][columns - 1] += grid[row + 1][columns - 1]
+
+      for row in range(rows - 2, -1, -1):
+          for column in range(columns - 2, -1, -1):
+              grid[row][column] += min(grid[row + 1][column], grid[row][column + 1])
+
+      return grid[0][0]