Submission #1041984

#	Time	Username	Problem	Language	Result	Execution time	Memory
1041984		YassineBenYounes	Trains (BOI24_trains)	C++17	16 / 100	25 ms	9916 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 = 1e6+5;
const int LOG = 22;
const int inf = 1e9;
const ll mod = 1e9+7;
const int sq = 320;
 
ll d[mx], x[mx];
 
ll segtree[mx];

void update(int node, int q_low, int q_high, int l, int r, ll v){
    if(l >= q_low && r <= q_high){
        segtree[node] += v;
        segtree[node] %= mod;
        return;
    }
    if(r < q_low || l > q_high){
        return;
    }
    update(2*node, q_low, q_high, l, (l+r)/2, v);
    update(2*node+1, q_low, q_high, (l+r)/2 + 1, r, v);
}
 
int _count(int n){
    int c = 0;
    while(n > 0){
        c+= (n&1);
        n/=2;
    }
    return c;
}
 
ll value(int node){
    ll ans = segtree[node];
    for(int j = (node / 2); j > 0;j/=2){
        ans += segtree[j];
        ans %= mod;
    }
    return ans;
}

int32_t main(){
    speed;
    int n;cin >> n;
    for(int i = 0; i < n;i++){
        cin >> d[i] >> x[i];
        x[i] = min(x[i], (long long)n);
    }
    int n1 = n;
    while(_count(n1) != 1){
        n1++;
    }
    update(1, 0, 0, 0, n1-1, 1);
    ll ans = 0;
    for(int i = 0; i < n;i++){
        ll v = value(i+n1) % mod;
        update(1, i+1, i+x[i], 0, n1-1, v);
        ans += v;
        ans %= 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: 16 / 16
• Subtask 4: 0 / 34
• Subtask 5: 0 / 29