Lweb and String
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/65536 K (Java/Others)
Total Submission(s): 4367 Accepted Submission(s): 1265
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→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
这题用了LIS的nlgn的解法,之后竟然是求字母出现的个数。。。
#include <cstdio> #include <vector> #include <cstring> #include <algorithm> using namespace std; const int maxn=1e5+5; char s[maxn]; int dp[maxn]; bool vis[30]; int main(){ //freopen("data.in","r",stdin); int t,c=0; scanf("%d",&t); while(t--){ scanf("%s",s); memset(vis,0,sizeof(vis)); int len=0; int n=strlen(s); for(int i=0;i<n;i++) vis[s[i]-‘a‘+0]++; /* dp[1]=s[0]; for(int i=1;i<n;i++){ if(s[i]>dp[len]) dp[++len]=s[i]; else { int x= lower_bound(dp,dp+len+1,s[i])-dp; dp[x]=s[i]; } } */ for(int i=0;i<30;i++) if(vis[i]) len++; printf("Case #%d: %d\n",++c,len); } }