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 $S$, $B$ is the set of natural
numbers.
Every injection $f: A \rightarrow B$ 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
$T, (1 \leq T \leq 20)$.
Then $T$ lines follow, the i-th line contains a
string $S$ only containing the lowercase letters, the length of $S$ will not
exceed $10^5$.
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
代码如下：
1 #include <iostream>
2 #include <cstdio>
3 #include <cstring>
4 #include<cmath>
5
6 using namespace std;
7
8 char s[100010];
9 int w[26];
10
11 int main()
12 {
13 int t;
14 int d = 0;
15 int sum;
16 scanf("%d",&t);
17 while(t--)
18 {
19 sum = 0;
20 scanf("%s",&s);
21 memset(w,0,sizeof(w));
22 for (int i=0;i<strlen(s);i++)
23 {
24 if (w[s[i]-‘a‘] == 0){
25 sum++;
26 w[s[i]-‘a‘] = 1;
27 }else
28 continue;
29 }
30 printf("Case #%d: %d\n",++d,sum);
31 }
32 return 0;
33 }
思路解析：
这题就是题意的问题。A不出来都是被样例迷惑了！样例毁一生2333333，有时候理解真的比直接敲更有用。