HDU 5842 Lweb and String （水题）

Lweb and String

题目链接：

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

Source

2016中国大学生程序设计竞赛 - 网络选拔赛


##题意：

给出一个字符串，确定一组字符到自然数的一一映射.
使得结果数串的严格LIS最大.


##题解：

由于字符串中仅含小写字母，那么结果最大就是26.
所以字符串中有多少个不同的字符，结果就是多少.


##代码：
``` cpp
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define LL long long
#define double long long
#define eps 1e-8
#define maxn 101000
#define mod 1000000007
#define inf 0x3f3f3f3f
#define mid(a,b) ((a+b)>>1)
#define IN freopen("in.txt","r",stdin);
using namespace std;

char str[maxn];

int main(int argc, char const *argv[])

{

//IN;

int t, ca=1; cin >> t;
while(t--)
{
    scanf("%s", str);

    int ans = 0;
    int sz = strlen(str);
    int state = 0;
    for(int i=0; i<sz; i++) {
        state |= 1<<(str[i]-'a');
    }

    for(int i=0; i<26; i++) {
        if(state & (1<<i)) ans++;
    }

    printf("Case #%d: %d\n", ca++, ans);
}

return 0;

}