HDU

找到最长串

然后进行n次KMP

#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 T, n;string a[maxn], s;int max_;void solve() {    for(int i = 0; i < n; ++i) {        int ok = 0;        int m = (int)a[i].size();        int f[m+3] ;                string p = a[i];        f[0] = f[1] = 0;        for(int i = 1; i <= m; ++i) {            int j = f[i];            while(j && p[i] != p[j]) j = f[j];            f[i+1] = p[i] == p[j] ? j+1 : 0;        }        int j = 0;        for(int i = 0; i < max_; ++i) {            while(j && s[i] != p[j]) j = f[j];            if(s[i] == p[j]) j++;            if(j == m) { ok = 1; break;}        }        if(!ok) { cout << "No\n"; return; }    }    cout << s << "\n";}int main() {    ios::sync_with_stdio(0); std::cin.tie(0);    cin >> T;    while(T--) {        cin >> n;        max_ = 0;        for(int i = 0; i < n; ++i) {            cin >> a[i];            if((int)a[i].size() > max_) { max_ = (int)a[i].size(); s = a[i]; }        }        solve();    }    return 0;}