学步园

http://acm.hdu.edu.cn/showproblem.php?pid=1238

//搜素 字符串题
#include <iostream>
#include <algorithm>
#include <string>
using namespace std;

string str[101];
int cmp (const string str1, const string str2)
{
 return (str1.length() < str2.length());
}
int main()
{
 int t, n, result;
 string strc, strr;
 int i, j, k;
 cin >> t;
 while (t-- && cin >> n) {
  result = 0;
  for (i = 0; i < n; i++) {
   cin >> str[i];
  }
  sort (str, str+n, cmp);//按长度排序所有字符串
  for (i = 0; i < str[0].length(); i++)
   for (j = 0; j+i <= str[0].length(); j++) {
    strc = str[0].substr(i, j);//求子字符串
    strr.assign(strc.rbegin(), strc.rend());//求逆向子字符串
    for (k = 1; k < n; k++) {
     if (str[k].find(strc) == string::npos &&
      str[k].find(strr) == string::npos)
      break;//没有找到匹配的子字符串
    }
    if (k == n && strc.length() > result)//找到了子字符串&&长度比之前都大
     result = strc.length();//保存
   }
  cout << result << endl;
 }
 return 0;
}