Submission #715734

#	Time	Username	Problem	Language	Result	Execution time	Memory
715734		bLIC	Necklace (Subtask 4) (BOI19_necklace4)	C++17	0 / 15	2 ms	340 KiB

necklace

/**
 *  Author: Anil Byar
**/

#include <bits/stdc++.h>
// #include <ext/pb_ds/assoc_container.hpp>
// #include <ext/pb_ds/tree_policy.hpp>

// using namespace __gnu_pbds;
using namespace std;

// template<class T>
// using ordered_set = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;



#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define sz(x) (int)(x).size()
#define ft first
#define sd second
#define pb push_back

// Source: https://codeforces.com/blog/entry/68809
// { start
void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '"' << x << '"';}
void __print(const string &x) {cerr << '"' << x << '"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifndef ONLINE_JUDGE
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif
// } end


typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<pii> vii;
typedef vector<ll> vl;
typedef vector<pll> vll;
typedef vector<vi> vvi;
typedef vector<vii> vvii;
typedef vector<vl> vvl;

#define dbg if(0)

const ll MOD = 1e9+7;
const ll MOD9 = 998244353;
const ll INFLL = 1e18+5;
const int INF = 1e9;
const int maxN = 101;
const int maxK = 8001;

void printbit(int x, int len) {string s="\n";while(len--){s=((x%2)?'1':'0')+s;x/=2;} cout<<s;}
ll power(ll x, ll y, ll mod){if (y==0) return 1;ll ret = power(x, y/2, mod);ret *= ret;ret%=mod;if (y&1) ret *= x;return ret%mod;}
ll modinv(ll x, ll mod = MOD) {return power(x, mod-2, mod);}

template<class T>
istream& operator>>(istream&in, vector<T>&v){
    for (T& x:v) in>>x;
    return in;
}
template<class T>
ostream& operator<<(ostream&out, vector<T>&v){
    for (T& x:v) out<<x<<' ';
    out<<'\n';
    return out;
}

vector<int> pi(const string &s, const string& t) {
	int n = (int)s.size();
	vector<int> pi_s(n);
	for (int i = 1, j = 0; i < n; i++) {
		while (j > 0 && s[j] != s[i]) { j = pi_s[j - 1]; }
		if (s[i] == s[j]) { j++; }
		pi_s[i] = j;
	}

    n = sz(t);
    vi ans(n);
    for (int i = 0, j = 0; i < n; i++){
        while(j>0 && s[j]!=t[i]) j = pi_s[j-1];
        if (s[j]==t[i]) j++;
        ans[i] = j;
    }
	return ans;
}


void solve(){
    string s, t;
    cin>>s>>t;
    int n = sz(s), m = sz(t);
    vvi pfx(n+5, vi(m+5));
    
    for (int i = 0;i<n;i++){
        pfx[i] = pi(s.substr(i, n-i), t);
        pfx[i].pb(0);
    }
    // cout<<pfx;
    int ans = 0, p1 = -1, p2 = -1;
    for (int i = 0;i<m;i++){
        for (int j = 0;j<n;j++){
            int len = pfx[j][i];
            int len1 = (i>=len && j+len<n)?pfx[j+len][i-len]:0;
            // debug(i, j, len, len1);
            if (len+len1>ans){
                ans = len+len1;
                p2 = i-ans+1;
                p1 = j;
            }
            debug(ans, p1, p2);
        }
    }
    reverse(all(t));
    for (int i = 0;i<n;i++){
        pfx[i] = pi(s.substr(i, n-i), t);
        pfx[i].pb(0);
    }
    for (int i = 0;i<m;i++){
        for (int j = 0;j<n;j++){
            int len = pfx[j][i];
            int len1 = (i>=len && j+len<n)?pfx[j+len][i-len]:0;
            if (len+len1>ans){
                ans = len+len1;
                p2 = m-i-1;
                p1 = j;
            }
            debug(ans, p1, p2);
            // debug(ans, l, r);
        }
    }
    cout<<ans<<'\n';
    cout<<p1<<' '<<p2;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);


#ifndef ONLINE_JUDGE
    freopen("input.in", "r", stdin);
    freopen("output.out", "w", stdout);
    freopen("debug.dbg", "w", stderr);
    int tt = clock();
#endif

    int t=1, i = 1;
    // cin>>t;
    while(t--){
        // cout<<"Case #"<<i++<<": ";
        solve();
        cout<<'\n';
    }
#ifndef ONLINE_JUDGE
    cerr << "TIME = " << (float)(clock() - tt)/CLOCKS_PER_SEC << endl;
    tt = clock();
#endif
}

Compilation message (stderr)

necklace.cpp: In function 'int main()':
necklace.cpp:171:14: warning: unused variable 'i' [-Wunused-variable]
  171 |     int t=1, i = 1;
      |              ^
necklace.cpp:165:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  165 |     freopen("input.in", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
necklace.cpp:166:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  166 |     freopen("output.out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
necklace.cpp:167:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  167 |     freopen("debug.dbg", "w", stderr);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 15