【找出两个整数数组中同时出现的整数】Python实现

from collections import Counter

def find_common_elements(arr1, arr2):
    # 统计数组中每个数字的出现次数
    counter1 = Counter(arr1)
    counter2 = Counter(arr2)
    
    # 找出两个数组中同时出现的整数
    common_elements = set(arr1) & set(arr2)
    
    # 如果没有同时出现的整数，返回NULL
    if not common_elements:
        return "NULL"
    
    # 统计每个共同元素在两个数组中的最小出现次数
    count_dict = {}
    for num in common_elements:
        count_dict[num] = min(counter1[num], counter2[num])
    
    # 根据出现次数进行分类
    grouped = {}
    for num, count in count_dict.items():
        if count not in grouped:
            grouped[count] = []
        grouped[count].append(num)
    
    # 输出结果
    result = []
    for count in sorted(grouped.keys()):
        result.append(f"出现次数:{count}：" + ",".join(map(str, sorted(grouped[count]))))
    
    return "\n".join(result)

# 输入处理
arr1 = list(map(int, input().split(',')))
arr2 = list(map(int, input().split(',')))

# 调用函数并输出结果
print(find_common_elements(arr1, arr2))