Submission #1117810

#	Time	Username	Problem	Language	Result	Execution time	Memory
1117810		vjudge1	캥거루 (CEOI16_kangaroo)	C++17	6 / 100	2075 ms	336 KiB

kangaroo

#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define ld long double
#define endl '\n'
#define pb push_back
#define speedyboy ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define all(x) x.begin() , x.end()
#define F first
#define S second
#define pll pair<ll , ll>
#define pss pair<string , string>
#define YES cout << "YES" << endl;
#define NO cout << "NO" << endl;


const ll sz = 10 , INF = 1e18 , MOD = 998244353;
ll a[sz];

void open(){
    freopen("kangaroo.in" , "r" , stdin);
    freopen("kangaroo.out" , "w" , stdout);
}

ll i , j , k;
void solve(){
    ll n , l , r , ans = 0;
    cin >> n >> l >> r;
    for(i = 1 ; i <= n ; i++){
        a[i] = i;
    }
    do{
        if(a[1] == l && a[n] == r){
            bool ok = true;
            ll num = (a[1] > a[2] ? -1 : 1);
            for(i = 2 ; i < n ; i++){
                if((num == 1 && a[i + 1] >= a[i]) || (num == -1 && a[i + 1] <= a[i])){
                    ok = false;
                    break;
                }
                num *= -1;
            }
            if(ok) ans++;
        }
    }while(next_permutation(a + 1 , a + n + 1));
    cout << ans << endl;
}

signed main(){
    speedyboy;
    open;
    ll t = 1;
    //cin >> t;
    while(t--){
        solve();
    }
}

Compilation message (stderr)

kangaroo.cpp: In function 'int main()':
kangaroo.cpp:53:5: warning: statement is a reference, not call, to function 'open' [-Waddress]
   53 |     open;
      |     ^~~~
kangaroo.cpp:53:5: warning: statement has no effect [-Wunused-value]
kangaroo.cpp: In function 'void open()':
kangaroo.cpp:23:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   23 |     freopen("kangaroo.in" , "r" , stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
kangaroo.cpp:24:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   24 |     freopen("kangaroo.out" , "w" , stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 6 / 6
• Subtask 2: 0 / 30
• Subtask 3: 0 / 15
• Subtask 4: 0 / 49