Submission #681763

#	Time	Username	Problem	Language	Result	Execution time	Memory
681763		Cross_Ratio	Autobahn (COI21_autobahn)	C++14	100 / 100	123 ms	22088 KiB

autobahn

#include <bits/stdc++.h>
#define int long long
using namespace std;
int A[100005];
int B[100005];
int C[100005];
signed main() {
    cin.sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int N, K, X;
    cin >> N >> K >> X;
    int i, j;
    for(i=0;i<N;i++) {
        cin >> A[i] >> B[i] >> C[i];
    }
    vector<array<int, 2>> V;
    for(i=0;i<N;i++) {
        V.push_back({A[i], 1});
        V.push_back({A[i]+B[i], 2});
        V.push_back({C[i]+1, 3});
        V.push_back({A[i]+X, 4});
        V.push_back({A[i]+B[i]+X, 5});
        V.push_back({C[i]+1+X, 6});
    }
    sort(V.begin(),V.end());
    int ans = 0, val = 0, pl = 0, mi = 0, cnt1 = 0, cnt2 = 0;
    int prv = -1;
    for(auto it : V) {
        val += (it[0] - prv) * ( (cnt1 >= K ? pl : 0) - (cnt2 >= K ? mi : 0));
        if(it[1]==1) cnt1++;
        if(it[1]==2) pl++;
        if(it[1]==3) pl--, cnt1--;
        if(it[1]==4) cnt2++;
        if(it[1]==5) mi++;
        if(it[1]==6) mi--, cnt2--;
        prv = it[0];
        ans = max(ans, val);
        //cout << "Add in " << it[0] << ", type is " << it[1] << '\n';
        //cout << val << ' ' << cnt1 << ' ' << pl << ' ' << cnt2 << ' ' << mi << '\n';
    }
    cout << ans;
}

Compilation message (stderr)

autobahn.cpp: In function 'int main()':
autobahn.cpp:13:12: warning: unused variable 'j' [-Wunused-variable]
   13 |     int i, j;
      |            ^

• Subtask 1: 20 / 20
• Subtask 2: 30 / 30
• Subtask 3: 50 / 50