Submission #743194

#	Time	Username	Problem	Language	Result	Execution time	Memory
743194		vjudge1	Lasers (NOI19_lasers)	C++17	24 / 100	93 ms	1072 KiB

lasers

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

int l,r;

int main()
{
    cin >> l >> r;
    ios_base::sync_with_stdio(0); cin.tie(0);
    int cnt = 0;
    int mx = -1;
    for(int i=1;i<=r;++i)
    {
        int n; cin >> n;
        while(n--)
        {
            int len; cin >> len;
            mx = max(mx,len);
        }
    }
    if(mx > l/2)
    {
        int b = (mx-l/2);
        (l%2 == 0) ? cout << 2*b
                   : cout << 2*b-1;
    }
    else cout << "0\n";
    return 0;
}

Compilation message (stderr)

lasers.cpp: In function 'int main()':
lasers.cpp:10:9: warning: unused variable 'cnt' [-Wunused-variable]
   10 |     int cnt = 0;
      |         ^~~

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