标签：compose custom ibm sub clear com cin pen hdu
InputThe input contains several tasks. Each task begins with a line containing a positive integer N, the number of trademarks (2 ≤ N ≤ 4000). The number is followed by N lines, each containing one trademark. Trademarks will be composed only from lowercase letters, the length of each trademark will be at least 1 and at most 200 characters.
After the last trademark, the next task begins. The last task is followed by a line containing zero.OutputFor each task, output a single line containing the longest string contained as a substring in all trademarks. If there are several strings of the same length, print the one that is lexicographically smallest. If there is no such non-empty string, output the words “IDENTITY LOST” instead.Sample Input
3 aabbaabb abbababb bbbbbabb 2 xyz abc 0
Sample Output
abb IDENTITY LOST
题意：和前一题几乎一模一样，只是没有反转的情况（变简单了）
题解：枚举第一个的子串进行kmp
#include<map> #include<set> #include<cmath> #include<queue> #include<stack> #include<vector> #include<cstdio> #include<iomanip> #include<cstdlib> #include<cstring> #include<iostream> #include<algorithm> #define pi acos(-1) #define ll long long #define mod 10007 #define ls l,m,rt<<1 #define rs m+1,r,rt<<1|1 using namespace std; const double g=10.0,eps=1e-9; const int N=4000+5,maxn=(1<<18)-1,inf=0x3f3f3f3f; int Next[N],slen,plen; string a[N],ptr,str; void getnext() { int k=-1; Next[0]=-1; for(int i=1;i<slen;i++) { while(k>-1&&str[k+1]!=str[i])k=Next[k]; if(str[k+1]==str[i])k++; Next[i]=k; } } bool kmp() { int k=-1; for(int i=0;i<plen;i++) { while(k>-1&&str[k+1]!=ptr[i])k=Next[k]; if(str[k+1]==ptr[i])k++; if(k==slen-1)return 1; } return 0; } int main() { ios::sync_with_stdio(false); cin.tie(0); // cout<<setiosflags(ios::fixed)<<setprecision(2); int n; while(cin>>n,n){ for(int i=0;i<n;i++)cin>>a[i]; string ans=""; for(int i=1;i<=a[0].size();i++) { for(int j=0;j<=a[0].size()-i;j++) { str=a[0].substr(j,i); slen=str.size(); getnext(); bool flag=1; for(int k=1;k<n;k++) { ptr=a[k]; plen=a[k].size(); if(kmp())continue; flag=0; break; } if(flag) { if(ans.size()<str.size())ans=str; else if(ans.size()==str.size()&&str<ans)ans=str; } } } if(ans!="")cout<<ans<<endl; else cout<<"IDENTITY LOST"<<endl; } return 0; }
标签：compose custom ibm sub clear com cin pen hdu
原文地址：http://www.cnblogs.com/acjiumeng/p/6825013.html
