Submission #66874

#	Time	Username	Problem	Language	Result	Execution time	Memory
66874		Benq	Sailing Race (CEOI12_race)	C++14	75 / 100	3060 ms	4832 KiB

race

#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
 
using namespace std;
using namespace __gnu_pbds;
 
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;
 
typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;
 
typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;
 
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;
 
#define FOR(i, a, b) for (int i=a; i<(b); i++)
#define F0R(i, a) for (int i=0; i<(a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)
 
#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()
 
const int MOD = 1000000007;
const ll INF = 1e18;
 
bool ok[501][501];
int N,k;
 
int nor(int x) { x = (x%N+N)%N; if (x == 0) x += N; return x; }
template<class T> void MX(T& a, T b) { a = max(a,b); }

int alt[2][501][501];

pi solve0() {
    FOR(len,2,N) FOR(i,1,N+1) {
        int en = nor(i+len);
        FOR(j,1,len) {
            int m = nor(i+j);
            int ex = max(alt[0][m][en],alt[1][i][m])+1;
            if (ok[i][m]) MX(alt[0][i][en],ex);
            if (ok[en][m]) MX(alt[1][i][en],ex);
        }
    }
    
    pi ret = {0,0};
    FOR(i,1,N+1) FOR(j,1,N+1) if (ok[i][j]) 
        MX(ret,{max(alt[1][i][j],alt[0][j][i])+1,i});
    return ret;
}

int no[2][501][501];

pi ret = {0,0};
    
void test1(int len, int i) {
    pi yes = {-MOD,-MOD};
    int en = nor(i+len);
    int existsEdge = 0;
    for (int j = len-1; j >= 0; --j) {
        int m = nor(i+j);
        if (ok[m][en]) {
            MX(no[0][i][en],no[0][i][m]+1);
            if (existsEdge) MX(yes,{no[0][i][en],existsEdge});
        }
        if (ok[m][i]) existsEdge = m;
    }
    MX(ret,{yes.f+alt[0][en][i]+1,yes.s});
}

void test2(int len, int i) {
    int en = nor(i+len);
    no[0][i][en] = -MOD;
    for (int j = 0; j < len; ++j) {
        int m = nor(i+j);
        if (j && ok[m][i]) MX(ret,{no[0][i][en]+alt[1][m][en]+1,m});
        if (ok[m][en]) MX(no[0][i][en],no[0][i][m]+1);
    }
}

void test3(int len, int i) {
    pi yes = {-MOD,-MOD};
    int st = nor(i-len);
    int existsEdge = 0;
    for (int j = len-1; j >= 0; --j) {
        int m = nor(i-j);
        if (ok[m][st]) {
            MX(no[1][st][i],no[1][m][i]+1);
            if (existsEdge) MX(yes,{no[1][st][i],existsEdge});
        }
        if (ok[m][i]) existsEdge = m;
    }
    // cout << "OH " << yes.f+alt[1][i][st]+1 << " " << yes.f << " " << yes.s << " " << i << " " << st << "\n";
    MX(ret,{yes.f+alt[1][i][st]+1,yes.s});
}

void test4(int len, int i) {
    int st = nor(i-len);
    no[1][st][i] = -MOD;
    for (int j = 0; j < len; ++j) {
        int m = nor(i-j);
        if (j && ok[m][i]) MX(ret,{no[1][st][i]+alt[0][st][m]+1,m});
        if (ok[m][st]) MX(no[1][st][i],no[1][m][i]+1);
    }
}

pi solve1() {
    F0R(i,2) FOR(j,1,N+1) FOR(k,1,N+1) {
        if (j != k) no[i][j][k] = -MOD;
        else no[i][j][k] = 0;
    }
    FOR(len,1,N) FOR(i,1,N+1) {
        test1(len,i);
        test2(len,i);
        test3(len,i);
        test4(len,i);
    }
    
    return ret;
}
 
int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> N >> k;
    FOR(i,1,N+1) {
        int x; 
        while (cin >> x) {
            if (x == 0) break;
            ok[i][x] = 1;
        }
    }
    pi t = solve0();
    if (k == 1) MX(t,solve1());
    cout << t.f << "\n" << t.s;
}
 
/* Look for:
* the exact constraints (multiple sets are too slow for n=10^6 :( ) 
* special cases (n=1?)
* overflow (ll vs int?)
* array bounds
*/

• Subtask 1: 75 / 100