Submission #1035317

#	Time	Username	Problem	Language	Result	Execution time	Memory
1035317		Requiem	Sailing Race (CEOI12_race)	C++17	0 / 100	3094 ms	9824 KiB

race

#include<bits/stdc++.h>
//#define int long long
#define pb push_back
#define fast ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
#define MOD 1000000007
#define inf 1e18
#define fi first
#define se second
#define FOR(i,a,b) for(int i=a;i<=b;i++)
#define FORD(i,a,b) for(int i=a;i>=b;i--)
#define sz(a) ((int)(a).size())
#define endl '\n'
#define pi 3.14159265359
#define TASKNAME "sailrace"
template<typename T> bool maximize(T &res, const T &val) { if (res < val){ res = val; return true; }; return false; }
template<typename T> bool minimize(T &res, const T &val) { if (res > val){ res = val; return true; }; return false; }
using namespace std;
typedef pair<int,int> ii;
typedef pair<int,ii> iii;
typedef vector<int> vi;
const int MAXN = 3e5 + 9;
string str;
int n, k;
vector<int> g[MAXN];

void extract(int curId){
     int num = 0;
//     cout << str << endl;
     str = str + ' ';
     for(int i = 0; i < str.length(); i++){
         if (str[i] != ' ') {
             num = num * 10 + (str[i] - '0');
//             cout << num << ' ' << str[i] - '0' << endl;
         }
         else {
             if (num != 0) {
                 g[curId].pb(num);
//                 cout << curId << ' ' << num << endl;
             }
             else break;

             num = 0;

         }
     }
}

namespace subtask1{
    bool check(){
         return k == 0;
    }

    int dp[2][502][502], backward = 0;

    int goBack(int id){
        return (id - backward <= 0) ? id - backward + n : (id - backward);
    }

    int goUp(int id){
        return (id + backward) - ((id + backward > n) ? (n) : 0);
    }



    int memo(int state, int Larc, int Rarc){
        int mx = 0;
        for(int len = n; len >= 1; len--){
            for(int Larc = 1, Rarc = Larc + len - 1; Rarc <= n; Rarc++, Larc++){
                for(int state = 0; state < 2; state++){
                    int cur = goUp((state) ? Rarc : Larc);
                    if (dp[state][Larc][Rarc] < 0) continue;

//                    cout << cur << ' ' << state << ' ' << Larc << ' ' << Rarc << ' ' << dp[state][Larc][Rarc] << endl;
                    if (state == 0){
                        for(auto v: g[cur]){
                            int curV = goBack(v);
                            if (curV > Larc and curV <= Rarc) {
//                                maximize(dp[0][Larc][Rarc], 1 + max(memo(0, curV, Rarc), memo(1, Larc + 1, curV)));
                                maximize(dp[0][curV][Rarc],     dp[0][Larc][Rarc] + 1);
                                maximize(dp[1][Larc + 1][curV], dp[0][Larc][Rarc] + 1);
                            }
                        }
                    }
                    else{
                        for(auto v: g[cur]){
                            int curV = goBack(v);
                            if (curV >= Larc and curV < Rarc) {
//                                maximize(dp[1][Larc][Rarc], 1 + max(memo(0, curV, Rarc - 1), memo(1, Larc, curV)));
                                maximize(dp[0][curV][Rarc - 1], dp[1][Larc][Rarc] + 1);
                                maximize(dp[1][Larc][curV],     dp[1][Larc][Rarc] + 1);
                            }
                        }
                    }

                }
            }
        }

        for(int i = 1; i <= n; i++){
            for(int j = 1; j <= n; j++){
                maximize(mx, dp[0][i][j]);
                maximize(mx, dp[1][i][j]);
            }
        }
        return mx;
    }

    void solve(){
        int bestI = 0, res = 0;
        for(int i = 1;i <= n; i++){
            memset(dp, -0x3f, sizeof(dp));
            backward = i - 1;
            dp[0][1][n] = 0;
            int mx = memo(0, 1, n);
            if (maximize(res, mx)){
                bestI = i;
            }
        }
        cout << res << endl;
    }
}

main()
{
    fast;
    if (fopen(TASKNAME".inp","r")){
        freopen(TASKNAME".inp","r",stdin);
        freopen(TASKNAME".out","w",stdout);
    }
    cin >> n >> k;
    cin.ignore();
    for(int i = 1; i <= n; i++){
        getline(cin, str);
        extract(i);
    }

    if (subtask1::check()) return subtask1::solve(), 0;
    subtask1::solve();


}
/**
Warning:
- MLE / TLE?
- Gioi han mang?
- Gia tri max phai luon gan cho -INF
- long long co can thiet khong?
- tran mang.
- code can than hon
- Nho sinh test de tranh RTE / TLE

--> Coi lai truoc khi nop
**/

Compilation message (stderr)

race.cpp: In function 'void extract(int)':
race.cpp:30:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |      for(int i = 0; i < str.length(); i++){
      |                     ~~^~~~~~~~~~~~~~
race.cpp: In function 'void subtask1::solve()':
race.cpp:109:13: warning: variable 'bestI' set but not used [-Wunused-but-set-variable]
  109 |         int bestI = 0, res = 0;
      |             ^~~~~
race.cpp: At global scope:
race.cpp:123:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  123 | main()
      | ^~~~
race.cpp: In function 'int main()':
race.cpp:127:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  127 |         freopen(TASKNAME".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
race.cpp:128:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  128 |         freopen(TASKNAME".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 100