quxes code

Author: greyshell

basic/quxes_fb.py

@@ -0,0 +1,94 @@
+# !/usr/bin/env python3
+
+# author: greyshell
+
+"""
+On a mysterious island there are creatures known as Quxes which come in three colors: red, green, and blue. One power
+of the Qux is that if two of them are standing next to each other, they can transform into a single creature of the
+third color.
+
+Given N Quxes standing in a line, determine the smallest number of them remaining after any possible sequence of such
+transformations.
+
+For example, given the input ['R', 'G', 'B', 'G', 'B'], it is possible to end up with a single Qux through the
+following steps:
+
+        Arrangement       |   Change
+----------------------------------------
+['R', 'G', 'B', 'G', 'B']      | (R, G) -> B
+['B', 'B', 'G', 'B']            | (B, G) -> R
+['B', 'R', 'B']                  | (R, B) -> G
+['B', 'G']                        | (B, G) -> R
+['R']
+"""
+
+d = list()
+
+count = 0
+
+
+def transform(a, b):
+    s = 82 + 71 + 66
+    color = dict()
+    color[82] = 'R'
+    color[71] = 'G'
+    color[66] = 'B'
+    c = s - (ord(a) + ord(b))
+    return color[c]
+
+
+def backtrack(i, j):
+    global count
+    if len(d) == j:
+        print(d)
+        exit(0)
+    elif d[i] != d[j]:
+        a1 = d.pop(i)
+        a2 = d.pop(i)
+        c = transform(a1, a2)
+        d.insert(i, c)
+        count += 1
+        return i
+    elif d[i] == d[j]:
+        k = backtrack(i + 1, j + 1)
+        a1 = d.pop(k - 1)
+        a2 = d.pop(k - 1)
+        c = transform(a1, a2)
+        d.insert(k - 1, c)
+        count += 1
+        return k - 1
+
+
+def solution(quexes):
+    """
+    time complexity: O(n)
+    space complexity: O(n) for the storing the
+    :param quexes:
+    :return:
+    """
+    global count
+    for ch in quexes:
+        d.append(ch)
+
+    n = len(d)
+
+    while count < n:
+        if d[0] == d[1]:
+            backtrack(0, 1)
+        else:
+            c = transform(d.pop(1), d.pop(0))
+            d.insert(0, c)
+        count += 1
+
+    return d
+
+
+def main():
+    quxes = ['R', 'G', 'B', 'B', 'B', 'R']
+    print(quxes)
+    result = solution(quxes)
+    print(f"{result}")
+
+
+if __name__ == '__main__':
+    main()