题目链接:http://acm.hust.edu.cn/vjudge/problem/viewProblem.action?id=51171
题意:给你n个串的集合D,然后求一个长度最短的串s,使得使得s大于等于D中一半的串,又同时小于另一半串。
思路:直接暴力。先对n个串排序,然后选择第n/2-1个串,从第一个字母开始找,在后面添加26个字母枚举,直至找到目标串。
code:
#include <iostream>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <cstring>
#include <sstream>
#include <string>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <bitset>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
const int INF=0x3fffffff;
const int inf=-INF;
const int N=1000000;
const int M=2005;
const int mod=1000000007;
const double pi=acos(-1.0);
#define cls(x,c) memset(x,c,sizeof(x))
#define cpy(x,a) memcpy(x,a,sizeof(a))
#define fr(i,s,n) for (int i=s;i<=n;i++)
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
#define lrt rt<<1
#define rrt rt<<1|1
#define middle int m=(r+l)>>1
#define lowbit(x) (x&-x)
#define pii pair<int,int>
#define mk make_pair
#define IN freopen("in.txt","r",stdin);
#define OUT freopen("out.txt","w",stdout);
string s[M];
int n;
void sol()
{
sort(s,s+n);
//fr(i,0,n-1) cout<<s[i]<<endl;
string s1=s[n/2-1],s2=s[n/2],t="",p="";
for (int i=0;;++i)
{
for (char c='A';c<='Z';++c)
{
t=p+c;
if(t>=s1&&t<s2){cout<<t<<endl;return;}
}
p+=s1[i];
}
}
int main()
{
while (~scanf("%d",&n)&&n)
{
fr(i,0,n-1) cin>>s[i];
sol();
}
}