题解 | 牛牛的考试

T = int(input())
for _ in range(T):
    # 一次性读取4个输入并计算长度，减少变量定义
    lengths = [len(input()) for _ in range(4)]
    labels = ["A", "B", "C", "D"]

    min_len = min(lengths)
    max_len = max(lengths)
    min_count = lengths.count(min_len)
    max_count = lengths.count(max_len)

    # 简化条件判断逻辑
    if min_count == 1 and max_count != 1:
        print(labels[lengths.index(min_len)])
    elif max_count == 1 and min_count != 1:
        print(labels[lengths.index(max_len)])
    else:
        print("C")