제출 #796371

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
796371		12345678	Lasers (NOI19_lasers)	C++17	41 / 100	1076 ms	6364 KiB

lasers

#include <bits/stdc++.h>

using namespace std;

const int nx=5e5+5, mx=1e6+5;
int n, l, x, s[nx], ans;
bool c[mx];

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>l>>n;
    for (int i=0; i<n; i++)
    {
        cin>>s[i];
        vector<int> v(s[i]+2);
        for (int j=1; j<=s[i]; j++) cin>>v[j], v[j]+=v[j-1];
        v[s[i]+1]=INT_MAX;
        if (v[s[i]]>(l/2))
        {
            for (int j=1; j<=v[s[i]]; j++)
            {
                auto x=*prev(lower_bound(v.begin()+1, v.end(), j));
                if ((v[s[i]]-x)>l-j) c[j]=1;
            }
        }
    }
    for (int i=1; i<=mx; i++) if (c[i]) ans++;
    cout<<ans;
}

컴파일 시 표준 에러 (stderr) 메시지

lasers.cpp: In function 'int main()':
lasers.cpp:28:38: warning: iteration 1000004 invokes undefined behavior [-Waggressive-loop-optimizations]
   28 |     for (int i=1; i<=mx; i++) if (c[i]) ans++;
      |                                   ~~~^
lasers.cpp:28:20: note: within this loop
   28 |     for (int i=1; i<=mx; i++) if (c[i]) ans++;
      |                   ~^~~~

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