字符提取,输出字符串。排序时注意key是什么,这里有个升序和倒序的技巧,本来是倒序的,在key里的x[0]前加个负号即为升序。
while True: try: str1 = str(input()) cha = [] for i in range(len(str1)): flag = 0 for j in range(len(cha)): if(ord(str1[i]) == cha[j][0]): cha[j][1] += 1 flag = 1 break if(flag == 0): cha.append([ord(str1[i]),1]) cha.sort(key = lambda x:(x[1],-x[0]),reverse = True) res_str = '' for i in range(len(cha)): res_str += chr(cha[i][0]) print(res_str) except: break