减少字符串数组中序列的最佳方法

def find_least_frequent_string(arr):
    # 创建一个空字典来存储字符串及其出现次数
    freq_dict = {}
    
    # 遍历字符串数组，并将每个字符串及其出现次数添加到字典中
    for s in arr:
        if s in freq_dict:
            freq_dict[s] += 1
        else:
            freq_dict[s] = 1
    
    # 找到出现次数最少的字符串及其出现次数
    least_freq_string = None
    min_freq = float('inf')
    for s, freq in freq_dict.items():
        if freq < min_freq:
            min_freq = freq
            least_freq_string = s
    
    return least_freq_string