python saddle points

python/saddle-points/saddle_points.py

@@ -0,0 +1,18 @@
+def saddle_points(matrix):
+    # Check a single point in the matrix for if it's a saddle point
+    def saddle(point):
+        row = matrix[point[0]]
+        column = [row[point[1]] for row in matrix]
+        return max(row) == row[point[1]] and min(column) == column[point[0]]
+    # Raise a value error if the matrix lengths are not consistent
+    if len(set(list(map(len, matrix)))) > 1:
+        d = {i : len(m) for i, m in enumerate(matrix)}
+        d = sorted(list(set(list(d.values()))), reverse=True)
+        raise ValueError(f'Matrix Length of {d[-1]} instead of usual {d[0]} found.')
+    saddles = []
+    # Check every point for if it's a saddle point
+    for x, row in enumerate(matrix):
+        for y, point in enumerate(row):
+            if saddle((x, y)):
+                saddles.append({'row' : x + 1, 'column' : y + 1})
+    return saddles or [{}]