import sys while True: try: s=list(sys.stdin.readline().strip()) sets=set(s) dicts={} for i in sets: if i.isupper(): dicts[i]=[s.count(i),s.index(i),1] else: dicts[i]=[s.count(i),s.index(i),-1] print(dicts) dicts=sorted(dicts.items(),key=lambda x:(-x[1][0],x[1][2],x[1][1])) res=[] for i in range(len(dicts)): temp=[dicts[i][0],dicts[i][1][0]] res.append(':'.join(str(i) for i in temp)) print(';'.join(res)) except: break 这么搞不知道对不对，次数第一，同是小写和同是大写看先后顺序，大写在小写后，XXxyxy排出来是x:2;y:2;X:2