Submission #830308

#	Time	Username	Problem	Language	Result	Execution time	Memory
830308		vjudge1	Lasers (NOI19_lasers)	C++17	100 / 100	213 ms	4436 KiB

lasers

#include<bits/stdc++.h>
#define se second
#define fi first
using namespace std;
const int nmax = 5*1e5+5;
int lenwall[nmax];
vector<pair<int,int>>blck;
int main() {
    int L,R,X;
    int maxlen = 0;
    cin >> L >> R;
    for(int i=1; i<=R; i++) {
        cin >> X;
        int le=0;
        int ri=L;
        for(int j=1; j<=X; j++) {
            cin >> lenwall[j];
            le+=lenwall[j];
        }
        le-=lenwall[X];
        for(int k=X; k>=1; k--) {
            int l=le;
            int r=le+lenwall[k];
            int lt=ri-lenwall[k];
            int rt=ri;
            if(max(l,lt) < min(r,rt)) blck.push_back({max(l,lt), min(r,rt)});
            if(k!=1) le-=lenwall[k-1];
            ri-=lenwall[k];
        }
    }
    sort(blck.begin(), blck.end());
    int ans=0;
    int right=0, left=0;
    for(int i=0; i<blck.size(); i++) {
        if(right<blck[i].fi) {
            ans+=(right-left);
            left = blck[i].fi;
            right = blck[i].fi;
        }
        right = max(right, blck[i].se);
    }
    ans+=(right-left);
    cout << ans << endl;
    return 0;
}

Compilation message (stderr)

lasers.cpp: In function 'int main()':
lasers.cpp:34:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |     for(int i=0; i<blck.size(); i++) {
      |                  ~^~~~~~~~~~~~
lasers.cpp:10:9: warning: unused variable 'maxlen' [-Wunused-variable]
   10 |     int maxlen = 0;
      |         ^~~~~~

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