找出字符串中出现次数最多的字符。例如：bbcaaa，出现次数最多的字符是a。 c

代码如下：

def find_most_frequent_char(s):
    char_dict = {}
    for char in s:
        if char in char_dict:
            char_dict[char] += 1
        else:
            char_dict[char] = 1
    max_count = 0
    most_freq_char = ''
    for char, count in char_dict.items():
        if count > max_count:
            max_count = count
            most_freq_char = char
    return most_freq_char

s = 'bbcaaa'
print(find_most_frequent_char(s)) # 输出a