Submission #1041998

#	Time	Username	Problem	Language	Result	Execution time	Memory
1041998		YassineBenYounes	Trains (BOI24_trains)	C++17	0 / 100	2077 ms	1048576 KiB

Main

#include<bits/stdc++.h>
//#include<chrono>
//#include<random>
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef double db;
ll gcd(ll a , ll b) {return b ? gcd(b , a % b) : a ;} // greatest common divisor (PGCD)
ll lcm(ll a , ll b) {return (a * b) / gcd(a , b);} // least common multiple (PPCM)
int dx[8] = {1, 0, 0, -1, 1, 1, -1, -1};
int dy[8] = {0, 1, -1, 0, 1, -1, -1, 1};
#define endl "\n"
#define ss second
#define ff first
#define all(x) (x).begin() , (x).end()
#define pb push_back
#define vi vector<int>
#define vii vector<pair<int,int>>
#define vl vector<ll>
#define vll vector<pair<ll,ll>>
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pdd  pair<double,double>
#define vdd  vector<pdd>
#define speed ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define pbds tree<pii, null_type, less<pii>,rb_tree_tag, tree_order_statistics_node_update>
using namespace __gnu_pbds;
using namespace std;
//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
 
////////////////////Only Clear Code//////////////////////////
 
void usaco_problem(){
    freopen("milkvisits.in", "r", stdin);
    freopen("milkvisits.out", "w", stdout);
}
 
void init(){
    #ifndef ONLINE_JUDGE
 
freopen("input.txt", "r", stdin);
 
freopen("output.txt", "w", stdout);
 
#endif // ONLINE_JUDGE
}
const int mx = 1e5+5;
const int LOG = 22;
const int inf = 1e9;
const ll mod = 1e9+7;
const int sq = 320;
 
ll d[mx], x[mx];
 
vi graph[mx];
 
ll dp[mx], s[sq+5][sq+5];
 
int32_t main(){
    speed;
    int n;cin >> n;
    for(int i = 0; i < n;i++){
        cin >> d[i] >> x[i];
    }
    for(int i = 0; i < n;i++){
        if(d[i] == 0)continue;
        for(int j = i+1;j < n;j++){
            int diff = j-i;
            if((diff % d[i] == 0) && ((diff / d[i]) <= x[i])){
                graph[i].pb(j);
            }
        }
    }
    dp[0] = 1;
    ll ans = 0;
    for(int i = 0; i < n;i++){
        for(int j = 1; j < sq;j++){
            dp[i] += s[j][i % j];
            dp[i] %= mod;
            //cout << j << "   " << s[j][i%j] << endl;
        }
        //cout << i << " " << dp[i] << endl;
        ans += dp[i];
        ans %= mod;
        if(d[i] == 0)continue;
        if(d[i] >= sq){
            for(ll j = i+d[i];j <= min((long long)n-1, i+d[i]*x[i]);j+=d[i]){
                dp[j] += dp[i];
                dp[j] %= mod;
            }
            continue;
        }
        //cout << i << " " << d[i] << endl;
        s[d[i]][i % d[i]] += dp[i];
        s[d[i]][i % d[i]] %= mod;
    }
    cout << ans << endl;
}
 
/*
    NEVER GIVE UP!
    DOING SMTHNG IS BETTER THAN DOING NTHNG!!!
    Your Guide when stuck:
    - Continue keyword only after reading the whole input
    - Don't use memset with testcases
    - Check for corner cases(n=1, n=0)
    - Check where you declare n(Be careful of declaring it globally and in main)
*/

Compilation message (stderr)

Main.cpp: In function 'void usaco_problem()':
Main.cpp:36:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |     freopen("milkvisits.in", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:37:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |     freopen("milkvisits.out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp: In function 'void init()':
Main.cpp:43:8: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 | freopen("input.txt", "r", stdin);
      | ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:45:8: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   45 | freopen("output.txt", "w", stdout);
      | ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 8
• Subtask 2: 0 / 13
• Subtask 3: 0 / 16
• Subtask 4: 0 / 34
• Subtask 5: 0 / 29