Submission #524666

#	Time	Username	Problem	Language	Result	Execution time	Memory
524666		fcw	Necklace (Subtask 4) (BOI19_necklace4)	C++17	0 / 15	233 ms	65540 KiB

necklace

#include <bits/stdc++.h>
#define st first
#define nd second
using lint = int64_t;
constexpr int MOD = int(1e9) + 7;
constexpr int INF = 0x3f3f3f3f;
constexpr int NINF = 0xcfcfcfcf;
constexpr lint LINF = 0x3f3f3f3f3f3f3f3f;
const long double PI = acosl(-1.0);
// Returns -1 if a < b, 0 if a = b and 1 if a > b.
int cmp_double(double a, double b = 0, double eps = 1e-9) {
	return a + eps > b ? b + eps > a ? 0 : 1 : -1;
}
using namespace std;

vector<int> Z(const string& S) {
    vector<int> z(S.size());
    int l = -1, r = -1;
    for(int i = 1; i < int(S.size()); ++i) {
        z[i] = i >= r ? 0 : min(r - i, z[i - l]);
        while (i + z[i] < int(S.size()) && S[i + z[i]] == S[z[i]])
            z[i]++;
        if (i + z[i] > r) l = i, r = i + z[i];
    }
    return z;
}

array<int, 3>solve(string s, string t){
	array<int, 3>ans = {0, -1, -1};
	int n = (int)s.size(), m = (int)t.size();
	vector<int>z;
	vector<map<int, int>>w(n);
	for(int i=0;i<n;i++){
		z = Z(s + t);
		for(int j=0;j<m;j++){
			int d = min(z[n+j], n-i);
			if(d){
				if(ans[0] < d) ans = {d, i, j};
				int ni = i + d, nj = j + d;
				if(ni < n) w[ni][j] = max(w[ni][j], d);
				if(w[i].count(nj)){
					int nd = w[i][nj];
					if(ans[0] < d+nd) ans = {d+nd, i-nd, j};
				}
			}
		}
		rotate(s.begin(), s.begin() + 1, s.end());
	}
	return ans;
}

int main() {
	cin.tie(nullptr)->sync_with_stdio(false);
	string s, t;
	cin>>s>>t;
	int n = (int)s.size(), m = (int)t.size();
	array<int, 3>ans = solve(s, t);
	reverse(t.begin(), t.end());
	array<int, 3>rans = solve(s, t);
	if(ans[0] >= rans[0]){
		cout<<ans[0]<<"\n"<<ans[1]<<" "<<ans[2]<<"\n";
	}
	else{
		cout<<rans[0]<<"\n"<<rans[1]<<" "<<m-(rans[2]+rans[0])<<"\n";
	}

	return 0;
}
/*
[  ]Leu o problema certo???
[  ]Ver se precisa de long long
[  ]Viu o limite dos fors (é n? é m?)
[  ]Tamanho do vetor, será que é 2e5 em vez de 1e5??
[  ]Testar sample
[  ]Testar casos de  borda
[  ]1LL no 1LL << i
[  ]Testar mod (é 1e9+7, mesmo?, será que o mod não ficou negativo?)
*/

Compilation message (stderr)

necklace.cpp: In function 'int main()':
necklace.cpp:56:6: warning: unused variable 'n' [-Wunused-variable]
   56 |  int n = (int)s.size(), m = (int)t.size();
      |      ^

• Subtask 1: 0 / 15