Submission #1319881

#	Time	Username	Problem	Language	Result	Execution time	Memory
1319881		trainingdnns	Lasers (NOI19_lasers)	C++20	0 / 100	1 ms	332 KiB

lasers

#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main() {
    #ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    #endif
    ll l,r;
    cin>>l>>r;
    vector<vector<ll>> rows(r);
    for(ll i=0; i<r; i++) {
        ll x;
        cin>>x;
        for(ll j=0; j<x;j++) {
            ll xi;cin>>xi;
            rows[i].push_back(xi);
        }
    }
    ll ans=0;
    if(l%2==0) ans=rows[0][0]-floor(l/2)*2;
    else ans=rows[0][0]>floor(l/2) ? ((rows[0][0]-floor(l/2)-1)*2 + 1) : 0;
    cout<<ans;
}

Compilation message (stderr)

lasers.cpp: In function 'int main()':
lasers.cpp:7:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    7 |     freopen("input.txt", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
lasers.cpp:8:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    8 |     freopen("output.txt", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 14
• Subtask 3: 0 / 20
• Subtask 4: 0 / 21
• Subtask 5: 0 / 22
• Subtask 6: 0 / 13