Submission #568697

#	Time	Username	Problem	Language	Result	Execution time	Memory
568697		joshjms	Strange Device (APIO19_strange_device)	C++14	5 / 100	611 ms	48944 KiB

strange_device

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

#define int long long
#define ld long double
#define pb push_back
#define fi first
#define se second
#define debug(x) cout << #x << " => " << x << "\n";

const long long mod = 1e9 + 7;
const long long MAX = 1e18;

int n, a, b, L[1000005], R[1000005], s, m;
vector <pair<int,int>> ls;
int cnt, prv, ans;

void solve () {
    cin >> n >> a >> b;

    for(int i = 1; i <= n; i++) {
        cin >> L[i] >> R[i];
        s += R[i] - L[i] + 1;
    }

    if(MAX / a < b) {
        cout << s << "\n";
        return;
    }

    m = a * b;

    for(int i = 1; i <= n; i++) {
        L[i] %= m;
        R[i] %= m;

        if(R[i] < L[i]) {
            ls.pb({L[i], 0});
            ls.pb({m, 1});
            ls.pb({0, 0});
            ls.pb({R[i] + 1, 1});
        }
        else {
            ls.pb({L[i], 0});
            ls.pb({R[i] + 1, 1});
        }
    }
    
    sort(ls.begin(), ls.end());
    cnt = 0, prv = -1;

    // for(auto i : ls) cout << i.fi << " ";
    // cout << "\n";

    for(int i = 0; i < ls.size(); i++) {
        if(ls[i].se == 0) cnt++;
        else cnt--;

        if(i < ls.size() - 1 && ls[i].fi == ls[i + 1].fi) continue;

        if(cnt > 0 && prv == -1) {prv = ls[i].fi;}
        if(cnt == 0 && prv != -1) {ans += ls[i].fi - prv; prv = -1;}
    }

    cout << ans << "\n";

}

signed main () {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    solve();
}

Compilation message (stderr)

strange_device.cpp: In function 'void solve()':
strange_device.cpp:55:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   55 |     for(int i = 0; i < ls.size(); i++) {
      |                    ~~^~~~~~~~~~~
strange_device.cpp:59:14: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   59 |         if(i < ls.size() - 1 && ls[i].fi == ls[i + 1].fi) continue;
      |            ~~^~~~~~~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 5
• Subtask 3: 5 / 5
• Subtask 4: 0 / 5
• Subtask 5: 0 / 5
• Subtask 6: 0 / 20
• Subtask 7: 0 / 20
• Subtask 8: 0 / 30