Submission #1117807

#	Time	Username	Problem	Language	Result	Execution time	Memory
1117807		vjudge1	Kangaroo (CEOI16_kangaroo)	C++17	0 / 100	3 ms	592 KiB

kangaroo

#pragma GCC optimize("O3")
#include<bits/stdc++.h>
#define ll long long
#define endl "\n"
#define AI ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
using namespace std;
vector<ll>val;
vector<vector<ll>>edge;
vector<ll>check;
ll k,c=0;
int main()
{
    AI
    freopen("kangaroo.in", "r", stdin);
    freopen("kangaroo.out", "w", stdout);
    ll n,a,b,i,j,per=0;
    cin>>n>>a>>b;
    vector<ll>v(n);
    for(i=1;i<=n;i++)
    v[i-1]=i;
    do
    {
        if(v[0]!=a or v[n-1]!=b)
        continue;
        bool bo=true;
        for(i=1;i<n;i++)
        {
            if(i>2 and ((v[i-2]<v[i-1] and v[i-1]<v[i]) or (v[i-2]>v[i-1] and v[i-1]>v[i])))
            {
                bo=false;
                break;
            }
        }
        if(bo)
        per++;
    }while(next_permutation(v.begin(),v.end()));
    cout<<per;

}

Compilation message (stderr)

kangaroo.cpp: In function 'int main()':
kangaroo.cpp:16:16: warning: unused variable 'j' [-Wunused-variable]
   16 |     ll n,a,b,i,j,per=0;
      |                ^
kangaroo.cpp:14:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 |     freopen("kangaroo.in", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
kangaroo.cpp:15:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |     freopen("kangaroo.out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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