Submission #232629

#	Time	Username	Problem	Language	Result	Execution time	Memory
232629		limabeans	Strange Device (APIO19_strange_device)	C++17	5 / 100	615 ms	48532 KiB

strange_device

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

template<typename T>
void out(T x) { cout << x << endl; exit(0); }
#define watch(x) cout << (#x) << " is " << (x) << endl




typedef long long ll;
const ll mod = 1e9+7;
const int maxn = 1e6 + 5;



ll n, a, b;


ll getx(ll t) {
    return (t+t/b)%a;
}

ll gety(ll t) {
    return t%b;
}






ll merge(vector<pair<ll,ll>> v) {
    sort(v.begin(), v.end());
    // for (auto p: v) {
    // 	cout<<p.first<<" "<<p.second<<endl;
    // }
    
    ll res = 0;

    n = v.size();
    auto cur = v.front();
    for (int i=1; i<n; i++) {
	ll x=v[i].first;
	ll y=v[i].second;
	if (x>cur.second) {
	    res += cur.second-cur.first+1;
	    cur = v[i];
	} else {
	    cur.second=max(cur.second,y);
	}
    }
    res += cur.second-cur.first+1;
    return res;
}

vector<pair<ll,ll>> v;

int main() {
    ios_base::sync_with_stdio(false); cin.tie(0);  cout.tie(0);

    cin>>n>>a>>b;

    v.resize(n);
    for (int i=0; i<n; i++) {
	cin>>v[i].first>>v[i].second;
    }


    auto safe_lcm = [](ll x, ll y) {
	ll tmp = x / __gcd(x,y);
	if (tmp > 1e18/y) return (ll)1e18 + 1;
	return tmp*y;
    };

    ll lcm = safe_lcm(a, b);

    if (lcm>1e18) {
	//merge intervals
	ll res = merge(v);
	out(res);
    }



    vector<pair<ll,ll>> cv;
    
    for (int i=0; i<n; i++) {
	v[i].first %= (a*b);
	v[i].second %= (a*b);
	if (v[i].second>=v[i].first) {
	    cv.push_back(v[i]);
	} else {
	    
	    assert(v[i].first>v[i].second);
	    
	    cv.push_back({v[i].first,a*b});
	    cv.push_back({1,v[i].second});
	}
    }




    ll ans = merge(cv);
    out(ans);  

    return 0;
}

• 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