# How Voting Systems Work 2, Exercise 3: tactical switching and seats
# Ten districts (assumed, invented numbers). Move k Green voters in every
# district to their second choice, Blue, and watch the seats change.
districts = [
    {"Red": 40, "Blue": 35, "Green": 25},
    {"Red": 38, "Blue": 36, "Green": 26},
    {"Red": 42, "Blue": 33, "Green": 25},
    {"Red": 37, "Blue": 38, "Green": 25},
    {"Red": 39, "Blue": 34, "Green": 27},
    {"Red": 36, "Blue": 39, "Green": 25},
    {"Red": 41, "Blue": 34, "Green": 25},
    {"Red": 38, "Blue": 37, "Green": 25},
    {"Red": 40, "Blue": 35, "Green": 25},
    {"Red": 35, "Blue": 38, "Green": 27},
]

for k in range(0, 11, 2):
    seats = {"Red": 0, "Blue": 0, "Green": 0}
    for d in districts:
        moved = min(k, d["Green"])
        shifted = {"Red": d["Red"], "Blue": d["Blue"] + moved, "Green": d["Green"] - moved}
        seats[max(shifted, key=shifted.get)] += 1
    print(f"{k:2d} Green voters switch per district: seats Red {seats['Red']}, Blue {seats['Blue']}, Green {seats['Green']}")

# Output when run:
#  0 Green voters switch per district: seats Red 7, Blue 3, Green 0
#  2 Green voters switch per district: seats Red 6, Blue 4, Green 0
#  4 Green voters switch per district: seats Red 5, Blue 5, Green 0
#  6 Green voters switch per district: seats Red 2, Blue 8, Green 0
#  8 Green voters switch per district: seats Red 1, Blue 9, Green 0
# 10 Green voters switch per district: seats Red 0, Blue 10, Green 0