题解 | 异常值与缺失值(不使用numpy)

import sys

def main():
    data = sys.stdin.read().strip().split()
    if not data:
        return

    it = iter(data)
    n = int(next(it))
    i = 0
    new = []  # 存放新数据，缺失值设为0
    lack = [] # 记录缺失值位置
    cnt = 0.
    for a in range(n):
        k = float(next(it))

        if (k == (-1)):
            k = 0
            lack.append(i)
            i += 1 
            new.append(k)

        if (k<=800 and k>=200):
            new.append(k)
            i += 1

        if k != -1:
            cnt += k

    mean = cnt / (n - len(lack))

    for j in lack:
        new[j] = mean

    for num in new:
        print(f'{num:.4f}')

if __name__ == '__main__':
    main()