Submission #940821

#	Time	Username	Problem	Language	Result	Execution time	Memory
940821		GrindMachine	Strange Device (APIO19_strange_device)	C++17	100 / 100	378 ms	71620 KiB

strange_device

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a,b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a,b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*

read some solutions long time ago, remember some ideas from there

*/

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

void solve(int test_case)
{
    ll n,A,B; cin >> n >> A >> B;
    vector<pll> a(n+5);
    rep1(i,n) cin >> a[i].ff >> a[i].ss;

    ll g = gcd(A,B+1);
    ll k = A/g;
    ll period = 0;

    if(k > inf2/B){
        period = inf2;
    }
    else{
        period = k*B;
    }

    vector<pll> b;
 
    rep1(i,n){
        auto [l,r] = a[i];
        amin(r,l+period-1);
        l %= period, r %= period;
        if(l <= r){
            b.pb({l,r});
        }
        else{
            b.pb({l,period-1});
            b.pb({0,r});
        }
    }
 
    sort(all(b));
    ll mx_reach = -1;
    ll ans = 0;
 
    for(auto [l,r] : b){
        if(l > mx_reach){
            ans += r-l+1;
        }
        else{
            ans += max(r-mx_reach,0ll);
        }
 
        amax(mx_reach,r);
    }
 
    cout << ans << endl;
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}

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