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
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)
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.
2
aabcc
acdeaa
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。
#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;
}