solves minimum path sum

Author: anishLearnsToCode

README.md

@@ -1,7 +1,7 @@
 # LeetCode Algorithms
 
-![problems-solved](https://img.shields.io/badge/Problems%20Solved-442/2081-1f425f.svg)
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+![problems-solved](https://img.shields.io/badge/Problems%20Solved-460/2081-1f425f.svg)
+![problems-solved-java](https://img.shields.io/badge/Java-460/2081-1abc9c.svg)
 ![problems-solved-python](https://img.shields.io/badge/Python-186/2081-1abc9c.svg)
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@@ -61,6 +61,7 @@
 |  61  | [Rotate List](https://leetcode.com/problems/rotate-list)                                                                                                  |                                                                   [![Java](assets/java.png)](src/RotateList.java)                                                                    |                                                                                                                                   |
 |  62  | [Unique Paths](https://leetcode.com/problems/unique-paths)                                                                                                |                                                                   [![Java](assets/java.png)](src/UniquePaths.java)                                                                   |                                                                                                                                   |
 |  63  | [Unique Paths II](https://leetcode.com/problems/unique-paths-ii)                                                                                          |                                                                  [![Java](assets/java.png)](src/UniquePathII.java)                                                                   |                                                                                                                                   |
+|  64  | [Minimum Path Sum](https://leetcode.com/problems/minimum-path-sum)                                                                                        |                                                                 [![Java](assets/java.png)](src/MinimumPathSum.java)                                                                  |                                                                                                                                   |
 |  66  | [Plus One](https://leetcode.com/problems/plus-one)                                                                                                        |                                           [![Java](assets/java.png)](src/PlusOne.java) [![Python](assets/python.png)](python/plus_one.py)                                            |                                                                                                                                   |
 |  67  | [Add Binary](https://leetcode.com/problems/add-binary)                                                                                                    |                                         [![Java](assets/java.png)](src/AddBinary.java) [![Python](assets/python.png)](python/add_binary.py)                                          |                                                                                                                                   |
 |  69  | [Sqrt(x)](https://leetcode.com/problems/sqrtx)                                                                                                            |                                              [![Java](assets/java.png)](src/Sqrtx.java) [![Python](assets/python.png)](python/sqrt.py)                                               |                                                                                                                                   |

src/MinimumPathSum.java

@@ -0,0 +1,27 @@
+// https://leetcode.com/problems/minimum-path-sum
+// T: O(m * n)
+// S: O(1)
+
+public class MinimumPathSum {
+    public int minPathSum(int[][] grid) {
+        final int rows = grid.length, columns = grid[0].length;
+
+        // last row
+        for (int column = columns - 2 ; column >= 0 ; column--) {
+            grid[rows - 1][column] += grid[rows - 1][column + 1];
+        }
+
+        // last column
+        for (int row = rows - 2 ; row >= 0 ; row--) {
+            grid[row][columns - 1] += grid[row + 1][columns - 1];
+        }
+
+        for (int row = rows - 2 ; row >= 0 ; row--) {
+            for (int column = columns - 2 ; column >= 0 ; column--) {
+                grid[row][column] += Math.min(grid[row + 1][column], grid[row][column + 1]);
+            }
+        }
+
+        return grid[0][0];
+    }
+}