Submission #1076501

#	Time	Username	Problem	Language	Result	Execution time	Memory
1076501		vjudge1	Necklace (Subtask 4) (BOI19_necklace4)	C++17	15 / 15	222 ms	628 KiB

necklace

#include<bits/stdc++.h>
using namespace std;
#define FOR(i, a, b)  for(int i = (a), _b = (b); i <= _b; ++i)
#define FORD(i, b, a) for(int i = (b), _a = (a); i >= _a; --i)
#define REP(i, a, b)  for(int i = (a), _b = (b); i < _b;  ++i)
#define REPD(i, b, a) for(int i = (b), _a = (a); i > _a;  --i)
#define MASK(i) (1LL << (i))
#define BIT(mask, i) (((mask) >> (i)) & 1)
#define __builtin_popcount __builtin_popcountll
#define all(v) v.begin(), v.end()
#define ll long long
#define ull unsigned long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define sz(v) (int)v.size()
#define fi first
#define se second

mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll Rand(ll l, ll r) {return l + rng() % (r - l + 1);}

template<class X, class Y>
    bool minimize(X &x, const Y &y) {
        if (x > y) {
            x = y;
            return true;
        } else return false;
    }
template<class X, class Y>
    bool maximize(X &x, const Y &y) {
        if (x < y) {
            x = y;
            return true;
        } else return false;
    }
template<class T>
    T Abs(const T &x) {
        return (x < 0 ? -x : x);    
    }

const int mod = 1e9 + 7;
const int inf = 1e9;
const int N = 3e3 + 5;

int n, m;
string s, t;
int kmp[2][2 * N];

void KMP(int pos, string s, string t) {
    s = s + '#' + t;
    kmp[pos][0] = 0;
    int j = 0;
    REP(i, 1, s.size()) {
        while(j > 0 && s[i] != s[j]) j = kmp[pos][j - 1];
        if(s[i] == s[j]) ++j;
        kmp[pos][i] = j;
    }
}

void process() {
    cin >> s >> t;
    n = s.size(); m = t.size();
    int res(0), ls(0), lt(0);
    REP(type, 0, 2) {
        reverse(all(s));
        REP(i, 0, n - 1) {
            string tmp = s.substr(0, i + 1);
            reverse(all(tmp));
            reverse(all(t));
            KMP(0, tmp, t);

            reverse(all(t));
            tmp = s.substr(i + 1, n - i - 1);
            KMP(1, tmp, t);

            REP(j, 0, m - 1) {
                if(maximize(res, kmp[0][i + m - j] + kmp[1][j + n - i])) {
                    if(type == 0) ls = n - i - 1 - kmp[1][j + n - i];
                    else ls = i + 1 - kmp[0][i + m - j];
                    lt = j - kmp[1][j + n - i] + 1;
                }
            }
        }
    }
    cout << res << '\n';
    cout << ls << ' ' << lt << '\n';
}

signed main() {
    if(fopen("test.inp","r")) {
        freopen("test.inp","r",stdin);
        freopen("test.out","w",stdout);
    }
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    int ntests = 1;
    // cin >> ntests;
    while(ntests--) process();

    // cerr << "Time elapsed: " << (1.0 * clock() / CLOCKS_PER_SEC) << " s!\n";
    return 0;
}

Compilation message (stderr)

necklace.cpp: In function 'int main()':
necklace.cpp:91:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   91 |         freopen("test.inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
necklace.cpp:92:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   92 |         freopen("test.out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 15 / 15