A11114 | Diversity
时间限制1s
内存限制256MB
通过 / 提交0/0
题目描述
Calculate the minimum number of characters you need to change in the string $s$ , so that it contains at least $k$ different letters, or print that it is impossible.
String $s$ consists only of lowercase Latin letters, and it is allowed to change characters only to lowercase Latin letters too.
String $s$ consists only of lowercase Latin letters, and it is allowed to change characters only to lowercase Latin letters too.
输入格式
First line of input contains string $s$ , consisting only of lowercase Latin letters ( $1<=|s|<=1000$ , $|s|$ denotes the length of $s$ ).
Second line of input contains integer $k$ ( $1<=k<=26$ ).
Second line of input contains integer $k$ ( $1<=k<=26$ ).
输出格式
Print single line with a minimum number of necessary changes, or the word «impossible» (without quotes) if it is impossible.
输入输出样例
输入 #1
yandex 6
输出 #1
0
输入 #2
yahoo 5
输出 #2
1
输入 #3
google 7
输出 #3
impossible
In the first test case string contains $6$ different letters, so we don't need to change anything.
In the second test case string contains $4$ different letters: ${'a','h','o','y'}$ . To get $5$ different letters it is necessary to change one occurrence of $'o'$ to some letter, which doesn't occur in the string, for example, ${'b'}$ .
In the third test case, it is impossible to make $7$ different letters because the length of the string is $6$ .
In the second test case string contains $4$ different letters: ${'a','h','o','y'}$ . To get $5$ different letters it is necessary to change one occurrence of $'o'$ to some letter, which doesn't occur in the string, for example, ${'b'}$ .
In the third test case, it is impossible to make $7$ different letters because the length of the string is $6$ .
C++ 编辑器
输入
输出
可保存默认模板；新题优先使用已保存模板。
当前快捷键仅展示，暂不支持修改。
- 撤销
Ctrl / ⌘ + Z - 重做
Ctrl / ⌘ + Y - 查找
Ctrl / ⌘ + F - 全选
Ctrl / ⌘ + A - 复制
Ctrl / ⌘ + C - 剪切
Ctrl / ⌘ + X - 粘贴
Ctrl / ⌘ + V - 自动排版
工具栏排版按钮 - 草稿保存
编辑时自动保存到本机
历史
提交记录
状态说明时间源码
AI
作答助手
你好，我是作答助手。可以问思路、复杂度、样例含义或代码报错原因；不会直接给出完整 AC 代码。
确定要清空代码吗？
提交通过
评测结果：Accepted