saddle-points: Add tests for non-square matrices (NxM) (#1288)

There's no indication in the description that non square matrices (NxM)
are not covered in the provided saddle points definition.

Now the tests reflect that.

Author: Alexhans

exercises/saddle-points/canonical-data.json

@@ -1,6 +1,6 @@
 {
   "exercise": "saddle-points",
-  "version": "1.2.0",
+  "version": "1.3.0",
   "comments": [
     "Matrix rows and columns are 0-indexed."
   ],
@@ -117,6 +117,67 @@
           "column": 2
         }
       ]
+    },
+    {
+      "description": "Can identify saddle points in a non square matrix",
+      "property": "saddlePoints",
+      "input": {
+        "matrix": [
+          [3, 1, 3],
+          [3, 2, 4]
+        ]
+      },
+      "expected": [
+        {
+          "row": 0,
+          "column": 2
+        },
+        {
+          "row": 0,
+          "column": 0
+        }
+      ]
+    },
+    {
+      "description": "Can identify that saddle points in a single column matrix are those with the minimum value",
+      "property": "saddlePoints",
+      "input": {
+        "matrix": [
+          [2],
+          [1],
+          [4],
+          [1]
+        ]
+      },
+      "expected": [
+        {
+          "row": 1,
+          "column": 0
+        },
+        {
+          "row": 3,
+          "column": 0
+        }
+      ]
+    },
+    {
+      "description": "Can identify that saddle points in a single row matrix are those with the maximum value",
+      "property": "saddlePoints",
+      "input": {
+        "matrix": [
+          [2, 5, 3, 5]
+        ]
+      },
+      "expected": [
+        {
+          "row": 0,
+          "column": 1
+        },
+        {
+          "row": 0,
+          "column": 3
+        }
+      ]
     }
   ]
-}
+}

exercises/saddle-points/description.md

@@ -21,5 +21,7 @@ A matrix may have zero or more saddle points.
 Your code should be able to provide the (possibly empty) list of all the
 saddle points for any given matrix.
 
+The matrix can have a different number of rows and columns (Non square).
+
 Note that you may find other definitions of matrix saddle points online,
 but the tests for this exercise follow the above unambiguous definition.