feat(content): function signatures + test cases

backend/data/questions/check-if-it-is-a-straight-line.yaml

@@ -9,6 +9,26 @@ categories:
 patterns:
   - two-pointers
 
+function_signature: "def check_straight_line(coordinates: list[list[int]]) -> bool:"
+
+test_cases:
+  visible:
+    - input: { coordinates: [[1, 2], [2, 3], [3, 4], [4, 5], [5, 6], [6, 7]] }
+      expected: true
+    - input: { coordinates: [[1, 1], [2, 2], [3, 4], [4, 5], [5, 6], [7, 7]] }
+      expected: false
+  hidden:
+    - input: { coordinates: [[0, 0], [1, 1]] }
+      expected: true
+    - input: { coordinates: [[0, 0], [0, 1], [0, 2]] }
+      expected: true
+    - input: { coordinates: [[1, 0], [2, 0], [3, 0]] }
+      expected: true
+    - input: { coordinates: [[1, 1], [2, 2], [3, 3], [4, 4], [5, 5]] }
+      expected: true
+    - input: { coordinates: [[0, 0], [1, 1], [2, 3]] }
+      expected: false
+
 description: |
   You are given an array `coordinates`, where `coordinates[i] = [x, y]` represents the coordinate of a point. Check if these points make a straight line in the XY plane.