题解 | 字符串压缩算法

s = input().strip()
if not s:  # 处理空字符串
    print('')
    exit()

result = []
count = 0
current_char = s[0]

for i in range(1, len(s)):
    if s[i] == current_char:
        count += 1
    else:
        result.append(str(count) if count > 0 else current_char)
        if count > 0:
            result.append(current_char)
        count = 0
        current_char = s[i]

# 处理最后一个字符
if count > 0:
    result.append(str(count))
    result.append(current_char)
else:
    result.append(current_char)

print(''.join(result))
'''也可以完成一样的功能但是语句太复杂
str_num = list(map(str,input()))
str_len = len(str_num)
new_str =[]
count = 0
for i in range(0,str_len):
    if(i==0 ):
        if(str_num[i]==str_num[i+1]):
            count+=1
        else:
            new_str.append(str_num[i])
        continue
    elif(i>0 and i<str_len-1):
        if(str_num[i-1]==str_num[i] and str_num[i]==str_num[i+1]):
             count+=1
        else:
            if(str_num[i-1]==str_num[i] and str_num[i]!=str_num[i+1]):               
                new_str.append(count)
                new_str.append(str_num[i])
                count=0
            elif(str_num[i-1]!=str_num[i] and str_num[i]==str_num[i+1]):
                count+=1
            else:
                new_str.append(str_num[i])
                count=0
    else:
        if(count==0):
            new_str.append(str_num[i])
        else:
            new_str.append(count)
            new_str.append(str_num[i])       
for i in new_str:
    print(i,end='')
'''