Moved the exercises to the folder exercises/.

exercises/rectangles/example.py

@@ -0,0 +1,111 @@
+import itertools
+
+
+class corners():
+    def __init__(self, i, j):
+        # i, j are position of corner
+        self.i = i
+        self.j = j
+
+    def __str__(self):
+        return "[" + str(self.i) + ", " + str(self.j) + "]"
+
+
+# return corner on the same line
+def same_line(index, list):
+    for c in list:
+        if c.i == index:
+            return c
+
+
+# return corner on the same column
+def same_col(index, list):
+    for c in list:
+        if c.j == index:
+            return c
+
+
+def search_corners(input):
+    corner_list = []
+    for i in range(0, len(input)):
+        for j in range(0, len(input[i])):
+            if (input[i][j] == "+"):
+                corner_list.append(corners(i, j))
+    return corner_list
+
+
+# validate that 4 points form a
+# rectangle by comparing distance to
+# centroid of the rectangle for all corners
+def possible_rect(quartet):
+    mid_x = 0
+    mid_y = 0
+
+    # centroid
+    for c in quartet:
+        mid_x = mid_x + c.i / 4.0
+        mid_y = mid_y + c.j / 4.0
+
+    # reference distance using first corner
+    dx = abs(quartet[0].i - mid_x)
+    dy = abs(quartet[0].j - mid_y)
+
+    # Check all the same distance from centroid are equals
+    for i in range(1, len(quartet)):
+        if abs(quartet[i].i - mid_x) != dx or abs(quartet[i].j - mid_y) != dy:
+            return False
+    return True
+
+
+# validate path between two corners
+def path(c1, c2, input):
+    if c1.i == c2.i:
+        for j in range(min(c1.j + 1, c2.j + 1), max(c1.j, c2.j)):
+            if input[c1.i][j] != "-" and input[c1.i][j] != "+":
+                return False
+        return True
+    elif c1.j == c2.j:
+        for i in range(min(c1.i + 1, c2.i + 1), max(c1.i, c2.i)):
+            if input[i][c1.j] != "|" and input[i][c1.j] != "+":
+                return False
+        return True
+
+
+# validate path of rectangle
+def validate_rect(rect, input):
+    # validate connection at every corner
+    # with neighbours on the same line and col
+    for i in range(0, len(rect)):
+        l = same_line(rect[i].i, rect[0:i] + rect[i + 1:])
+        c = same_col(rect[i].j, rect[0:i] + rect[i + 1:])
+        if not path(rect[i], l, input) or not path(rect[i], c, input):
+            return False
+    return True
+
+
+# count number of rectangles
+# inside ASCII in input lines
+def count(lines=""):
+    nb_rect = 0
+    # test empty str
+    if lines == "":
+        return nb_rect
+
+    corners = search_corners(lines)
+    # no corners in str
+    if len(corners) == 0:
+        return nb_rect
+
+    # now let the magic begins
+    # all combinations of 4 corners (python ftw)
+    q = list(itertools.combinations(corners, r=4))
+    rectangles = []
+    for el in q:
+        if (possible_rect(el)):
+            rectangles.append(el)
+
+    # validate path in found rectangles
+    for rect in rectangles:
+        if (validate_rect(rect, lines)):
+            nb_rect = nb_rect + 1
+    return nb_rect