Submission #642234

#	Time	Username	Problem	Language	Result	Execution time	Memory
642234		devariaota	Lasers (NOI19_lasers)	C++17	100 / 100	112 ms	10016 KiB

lasers

#include <bits/stdc++.h>

using namespace std;

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    int l, r; cin >> l >> r;
    vector<pair<int, int>>seg;

    for(int i = 1; i <= r; i++){
        int left = 0, right = l;
        int x; cin >> x;
        vector<int>v(x);
        for(int j = 0; j < x; j++){
            cin >> v[j];
            left += v[j];
        }
        left -= v.back();

        for(int j = x - 1; j >= 0; j--){
            int l1 = left, r1 = left + v[j];
            int l2 = right - v[j], r2 = right;
            if(max(l1, l2) < min(r1, r2)){
                seg.emplace_back(max(l1, l2), min(r1, r2));
            }
            if(j) left -= v[j - 1];
            right -= v[j];
        }
    }

    sort(seg.begin(), seg.end());

    int ans = 0;
    int left = -1, right = -1;

    for(int i = 0; i < seg.size(); i++){
        if(right < seg[i].first){
            ans += (right - left);
            left = seg[i].first;
        }

        right = max(right, seg[i].second);
    }

    ans += (right - left);

    cout << ans << '\n';

    return 0;
}

Compilation message (stderr)

lasers.cpp: In function 'int main()':
lasers.cpp:36:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |     for(int i = 0; i < seg.size(); i++){
      |                    ~~^~~~~~~~~~~~

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