HDU 5842:Lweb and String (统计)

Lweb and String

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)
Total Submission(s): 261    Accepted Submission(s): 174


Problem 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 SB is the set of natural numbers.

Every injection f:AB 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,(1T20).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

 

这道题的题目很长,并且很容易让人误以为是一个求最大上升子序列长度的问题,其实只是一个计算不同字符个数的问题,别小看这种问题哦!很轻松就会超时的。

 

AC代码:
#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<algorithm>
using namespace std;
char c[100005];
int a[30];
int main()
{
    int n;
    scanf("%d%*c",&n);
    for(int i=1; i<=n; i++)
    {
        gets(c);
        int s=0;
        memset(a,0,sizeof(a));
        for(int j=0; j<(int)strlen(c); j++)
        {
            if(!a[c[j]-'a'])
            {
                a[c[j]-'a']=true;
                s++;
            }
        }
        printf("Case #%d: %d\n",i,s);
    }
    return 0;
}