Submission #303102

#	Time	Username	Problem	Language	Result	Execution time	Memory
303102		ant101	Sailing Race (CEOI12_race)	C++14	100 / 100	1049 ms	6520 KiB

race

#include <iostream>
#include <algorithm>
#include <cstring>
#include <iomanip>
#include <fstream>
#include <cmath>
#include <vector>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <map>
#include <stack>
#include <queue>
#include <assert.h>
#include <limits>
#include <cstdio>
#include <complex>
using namespace std;

typedef long long ll;
typedef long double ld;
typedef double db;
typedef string str;

typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;
#define mp make_pair
#define f first
#define s second

typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<ld> vd;
typedef vector<str> vs;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<pd> vpd;

#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) (x).rbegin(), (x).rend()
#define rsz resize
#define ins insert
#define ft front()
#define bk back()
#define pf push_front
#define pb push_back
#define eb emplace_back
#define lb lower_bound
#define ub upper_bound

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)

const int MOD = 1e9+7; // 998244353; // = (119<<23)+1
const int MX = 2e5+5;
const ll INF = 1e18;
const ld PI = 4*atan((ld)1);
const int dx[4] = {0,1,0,-1}, dy[4] = {1,0,-1,0};


namespace io {
    void setIn(string s) { freopen(s.c_str(),"r",stdin); }
    void setOut(string s) { freopen(s.c_str(),"w",stdout); }
    void setIO(string s = "") {
        ios_base::sync_with_stdio(0); cin.tie(0); // fast I/O
        // cin.exceptions(cin.failbit); // ex. throws exception when you try to read letter into int
        if (sz(s)) {
            setIn(s+".in");
            setOut(s+".out");
        } // for USACO
    }
}

using namespace io;

namespace input {
    template<class T> void re(complex<T>& x);
    template<class T1, class T2> void re(pair<T1,T2>& p);
    template<class T> void re(vector<T>& a);
    template<class T, size_t SZ> void re(array<T,SZ>& a);
    
    template<class T> void re(T& x) { cin >> x; }
    void re(double& x) { string t; re(t); x = stod(t); }
    void re(ld& x) { string t; re(t); x = stold(t); }
    template<class Arg, class... Args> void re(Arg& first, Args&... rest) {
        re(first); re(rest...);
    }
    
    template<class T> void re(complex<T>& x) { T a,b; re(a,b); x = cd(a,b); }
    template<class T1, class T2> void re(pair<T1,T2>& p) { re(p.f,p.s); }
    template<class T> void re(vector<T>& a) { F0R(i,sz(a)) re(a[i]); }
    template<class T, size_t SZ> void re(array<T,SZ>& a) { F0R(i,SZ) re(a[i]); }
}

namespace output {
    template<class T1, class T2> void pr(const pair<T1,T2>& x);
    template<class T, size_t SZ> void pr(const array<T,SZ>& x);
    template<class T> void pr(const vector<T>& x);
    template<class T> void pr(const set<T>& x);
    template<class T1, class T2> void pr(const map<T1,T2>& x);
    
    template<class T> void pr(const T& x) { cout << x; }
    template<class Arg, class... Args> void pr(const Arg& first, const Args&... rest) {
        pr(first); pr(rest...);
    }
    
    template<class T1, class T2> void pr(const pair<T1,T2>& x) {
        pr("{",x.f,", ",x.s,"}");
    }
    template<class T> void prContain(const T& x) {
        pr("{");
        bool fst = 1; for (const auto& a: x) pr(!fst?", ":"",a), fst = 0; // const needed for vector<bool>
        pr("}");
    }
    template<class T, size_t SZ> void pr(const array<T,SZ>& x) { prContain(x); }
    template<class T> void pr(const vector<T>& x) { prContain(x); }
    template<class T> void pr(const set<T>& x) { prContain(x); }
    template<class T1, class T2> void pr(const map<T1,T2>& x) { prContain(x); }
    
    void ps() { pr("\n"); }
    template<class Arg> void ps(const Arg& first) {
        pr(first); ps(); // no space at end of line
    }
    template<class Arg, class... Args> void ps(const Arg& first, const Args&... rest) {
        pr(first," "); ps(rest...); // print w/ spaces
    }
}

using namespace output;

using namespace input;

ll add(ll a, ll b) {
    a += b;
    if(a >= MOD) {
        a -= MOD;
    }
    return a;
}
ll sub(ll a, ll b) {
    a -= b;
    if(a < 0) {
        a += MOD;
    }
    return a;
}

ll mul(ll a, ll b) {
    return (a * b)%MOD;
}

void add_self(ll& a, ll b) {
    a = add(a, b);
}
void sub_self(ll& a, ll b) {
    a = sub(a, b);
}
void mul_self(ll& a, ll b) {
    a = mul(a, b);
}

#define pb push_back
void ckmx(int&x,int y){x=max(x,y);}
const int N=505;
vector<int> E[N];
int dp[N][N][2],n,k,tmp[N];
bool was[N][N][2];
int on(int l,int r,int v){
    return (l<=r&&l<=v&&r>=v)||(l>r&&(v<=r||v>=l));
}
int DP(int l,int r,int side){
    if(was[l][r][side])return dp[l][r][side];
    int u=side==0?l:r;
    was[l][r][side]=1;
    int L=side==0?(l==n?1:l+1):l;
    int R=side==1?(r==1?n:r-1):r;
    for(int v:E[u]){
        if(on(l,r,v)){
            ckmx(dp[l][r][side],1+max(DP(L,v,1),DP(v,R,0)));
        }
    }
    return dp[l][r][side];
}
int go[N][N][2],has[N][N];
int main(){
    scanf("%i %i",&n,&k);
    for(int i=1;i<=n;i++){
        while(1){
            int j;
            scanf("%i",&j);
            if(j==0)break;
            E[i].pb(j);
            has[i][j]=1;
        }
    }
    auto nxt=[&](int x){return x==n?1:x+1;};
    auto pre=[&](int x){return x==1?n:x-1;};
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++)tmp[j]=-N;
        tmp[i]=0;
        for(int j=i;;j=nxt(j)){
            go[i][j][0]=tmp[j];
            for(int r:E[j]){
                ckmx(tmp[r],tmp[j]+1);
            }
            if(j==pre(i))break;
        }
        for(int j=1;j<=n;j++)tmp[j]=-N;
        tmp[i]=0;
        for(int j=i;;j=pre(j)){
            go[i][j][1]=tmp[j];
            for(int r:E[j]){
                ckmx(tmp[r],tmp[j]+1);
            }
            if(j==nxt(i))break;
        }
    }
    int ans=-1,idx=0;
    for(int i=1;i<=n;i++){
        int now=DP(i,i==1?n:i-1,0);
        if(now>ans)ans=now,idx=i;
    }
    if(k==1){
        for(int i=1;i<=n;i++)for(int j=1;j<=n;j++)if(i!=j){
            if(go[i][j][0]!=0){
                int r=-1;
                for(int l=nxt(j);l!=i;l=nxt(l))if(has[l][i]){r=l;break;}
                if(r!=-1){
                    for(int z=nxt(r);z!=i;z=nxt(z))if(has[j][z]){
                        int now=1+go[i][j][0]+1+max(DP(nxt(r),z,1),DP(z,pre(i),0));
                        if(ans<now)ans=now,idx=r;
                    }
                }
            }
            if(go[i][j][1]!=0){
                int r=-1;
                for(int l=pre(j);l!=i;l=pre(l))if(has[l][i]){r=l;break;}
                if(r!=-1){
                    for(int z=pre(r);z!=i;z=pre(z))if(has[j][z]){
                        int now=1+go[i][j][1]+1+max(DP(z,pre(r),0),DP(nxt(i),z,1));
                        if(ans<now)ans=now,idx=r;
                    }
                }
            }
        }
    }
    printf("%i\n%i\n",ans,idx);
    return 0;
}

Compilation message (stderr)

race.cpp: In function 'void io::setIn(std::string)':
race.cpp:67:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   67 |     void setIn(string s) { freopen(s.c_str(),"r",stdin); }
      |                            ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
race.cpp: In function 'void io::setOut(std::string)':
race.cpp:68:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   68 |     void setOut(string s) { freopen(s.c_str(),"w",stdout); }
      |                             ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
race.cpp: In function 'int main()':
race.cpp:191:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  191 |     scanf("%i %i",&n,&k);
      |     ~~~~~^~~~~~~~~~~~~~~
race.cpp:195:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  195 |             scanf("%i",&j);
      |             ~~~~~^~~~~~~~~

• Subtask 1: 100 / 100