Submission #1225397

#	Time	Username	Problem	Language	Result	Execution time	Memory
1225397		MarwenElarbi	캥거루 (CEOI16_kangaroo)	C++17	0 / 100	1 ms	320 KiB

kangaroo

#include <bits/stdc++.h>
using namespace std;
const int nax=2e3+5;
const int MOD=1e9+7;
long long dp[nax][nax];
int main() {
    #ifndef ONLINE_JUDGE
        freopen("input.txt","r",stdin);
        freopen("output.txt","w",stdout);
    #endif
    int n,l,r;
    cin>>n>>l>>r;
    if(l>r) swap(l,r);
    dp[0][0]=1;
    long long ans=0;
    vector<int> arr;
    for (int i = 0; i < n; ++i)
    {
        arr.push_back(i+1);
    }
    do{
        if(arr[0]!=l) continue;
        if(arr.back()!=r) continue;
        bool test=true;
        for (int i = 1; i < n-1; ++i)
        {
            if(arr[i-1]<arr[i]&&arr[i]<arr[i+1]) test=false;
            if(arr[i-1]>arr[i]&&arr[i]>arr[i+1]) test=false;
        }
        /*if(test) for(auto u:arr) cout << u<<" ";
            cout <<endl;*/

        ans+=test;
    }while(next_permutation(arr.begin(),arr.end()));
    cout <<ans<<endl;
}

Compilation message (stderr)

kangaroo.cpp: In function 'int main()':
kangaroo.cpp:8:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    8 |         freopen("input.txt","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
kangaroo.cpp:9:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    9 |         freopen("output.txt","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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