Lweb and String
题目连接:
http://acm.hdu.edu.cn/showproblem.php?pid=5842
Description
Lweb has a string S.
Oneday, he decided to transform this string to a new sequence.
You need help him determine this transformation to get a sequence which has the longest LIS(Strictly Increasing).
You need transform every letter in this string to a new number.
A is the set of letters of S, B is the set of natural numbers.
Every injection f:A→B can be treat as an legal transformation.
For example, a String “aabc”, A={a,b,c}, and you can transform it to “1 1 2 3”, and the LIS of the new sequence is 3.
Now help Lweb, find the longest LIS which you can obtain from S.
LIS: Longest Increasing Subsequence. (https://en.wikipedia.org/wiki/Longest_increasing_subsequence)
Input
The first line of the input contains the only integer T,(1≤T≤20).
Then T lines follow, the i-th line contains a string S only containing the lowercase letters, the length of S will not exceed 105.
Output
For each test case, output a single line “Case #x: y”, where x is the case number, starting from 1. And y is the answer.
Sample Input
2
aabcc
acdeaa
Sample Output
Case #1: 3
Case #2: 4
Hint
题意
给你一个字符串,你可以把字符变成数字,然后让你构造一下,使得LIS最长是多少
题解:
其实就是字母个数,这个很显然嘛。
代码
#include<bits/stdc++.h>
using namespace std;
int cas;
string s;
int cnt[26];
int main(){
int t;scanf("%d",&t);
while(t--){
cin>>s;
int ans = 0;
memset(cnt,0,sizeof(cnt));
for(int i=0;i<s.size();i++){
cnt[s[i]-'a']++;
if(cnt[s[i]-'a']==1)ans++;
}
printf("Case #%d: %d\n",++cas,ans);
}
}