HDU

高端操作

#include <iostream>#include <cstdio>#include <cstdlib>#include <cstring>#include <string>#include <cmath>#include <set>#include <map>#include <stack>#include <queue>#include <ctype.h>#include <vector>#include <algorithm>#include <sstream>#define PI acos(-1.0)#define in freopen("in.txt", "r", stdin)#define out freopen("out.txt", "w", stdout)using namespace std;typedef long long ll;const int maxn = 500000 + 7, INF = 0x3f3f3f3f;int n;string str[maxn];int main() {    ios::sync_with_stdio(0);    cin.tie(0);    int T;    cin >> T;    while(T--) {        cin >> n;        int j = 0;        for(int i = 0; i < n; ++i) {            cin >> str[i];            if (str[j].length() < str[i].length()) j = i;        }        bool ok = true;        for(int i = 0; i < n; ++i) {            if(i != j && str[j].find(str[i]) == string::npos) {                ok = false;                break;            }        }        if(ok) cout << str[j] << endl;        else cout << "No" << endl;    }        return 0;}