Submission #1268911

#	Time	Username	Problem	Language	Result	Execution time	Memory
1268911		minhvule	Trains (BOI24_trains)	C++17	16 / 100	108 ms	6348 KiB

Main

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

#define int long long
#define fi first
#define se second
#define pb push_back
#define freo(task) if(fopen(task".inp", "r")){ freopen(task".inp", "r", stdin); freopen(task".out", "w", stdout); }
#define FOR(i, a, b) for(int i = (a), _b = (b); i <= _b; i ++)
#define FORD(i, a, b) for(int i = (a), _b = (b); i >= _b; i --)
#define bit(x, i) ((x >> i) & 1)
#define oo 1e18
#define all(v) v.begin(), v.end()

using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;
// mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
// ll rand(ll l, ll r) { assert(l <= r); return uniform_int_distribution<ll>(l, r)(rd); }
const int N = 1e5 + 5;
const int BLOCK = 320;
const int mod = 1e9 + 7;
const int base = 31;
int n, d[N], x[N], dp[N], sum[BLOCK + 10][BLOCK + 10], ans = 0;
vector<int> rem[N];
void add(int &a, int b){
    a += b;
    if(a >= mod) a -= mod;
}
void sub(int &a, int b){
    a -= b;
    if(a < 0) a += mod;
}
void solve(){
    cin>>n;
    FOR(i, 1, n){
        cin>>d[i]>>x[i];
        if(d[i] != 0) x[i] = min(x[i], (n - i) / d[i]);
        x[i] = i + d[i] * x[i];
    }
    dp[1] = 1;
    FOR(i, 1, n){
        FOR(j, 1, BLOCK - 1) add(dp[i], sum[j][i % j]);
        add(ans, dp[i]);
        if(d[i] != 0){
            if(d[i] >= BLOCK){
                for(int j = i + d[i]; i <= n; j += d[i]){
                    int t = i + j * d[i];
                    add(dp[t], dp[i]);
                }
            }
            else{
                add(sum[d[i]][i % d[i]], dp[i]);
                rem[x[i]].pb(i);
            }
        }
        for(int j : rem[i]) sub(sum[d[j]][j % d[j]], dp[j]);
    }
    cout<<ans;
}
int32_t main(){
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    freo("cuuho");
    int nTest = 1;
    // cin>>nTest;
    while(nTest --) solve();
    // cerr << "\nTime: " << 1.0 * clock() / CLOCKS_PER_SEC << "s\n";
    return 0;
}
/*



*/

Compilation message (stderr)

Main.cpp: In function 'int32_t main()':
Main.cpp:8:55: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    8 | #define freo(task) if(fopen(task".inp", "r")){ freopen(task".inp", "r", stdin); freopen(task".out", "w", stdout); }
      |                                                ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:64:5: note: in expansion of macro 'freo'
   64 |     freo("cuuho");
      |     ^~~~
Main.cpp:8:88: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    8 | #define freo(task) if(fopen(task".inp", "r")){ freopen(task".inp", "r", stdin); freopen(task".out", "w", stdout); }
      |                                                                                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:64:5: note: in expansion of macro 'freo'
   64 |     freo("cuuho");
      |     ^~~~

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