Submission #1275373

#	Time	Username	Problem	Language	Result	Execution time	Memory
1275373		vibeduck	Trains (BOI24_trains)	C++20	21 / 100	2095 ms	2116 KiB

Main

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

#define pb push_back
#define pf push_front
#define mp make_pair
#define fi first
#define se second
#define int long long
#define all(x) (x).begin(), (x).end()

typedef long double ld;
typedef long long ll;
typedef pair<ll,ll> pll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<bool> vb;
typedef vector<vector<int>> vvi;
typedef vector<vector<bool>> vvb;
typedef vector<vector<ll>> vvll;
typedef vector<string> vs;
typedef vector<vector<string>> vvs;
typedef vector<char> vc;
typedef vector<vector<char>> vvc;
typedef map<int, int> mii;
typedef unordered_map<int, int> umii;

const int mod = 1e9 + 7;
const int inf = INTMAX_MAX;
const bool tc = false;

inline void solve() {
    int n; cin >> n;
    vector<pii> a(n + 1);
    for (int i = 1; i <= n; i++) cin >> a[i].fi >> a[i].se;
    // {d, x}
    vi dp(n + 1); dp[1] = 1;
    for (int i = 2; i <= n; i++) {
        for (int j = i - 1; j >= 0; j--) {
            if (a[j].fi == 0) continue;
            if (((i - j) % a[j].fi) == 0 && (i - j) / a[j].fi <= a[j].se) {
                dp[i] += dp[j];
                dp[i] %= mod;
            }
        }
    }

    //for (int i = 1; i <= n; i++) cout << dp[i] << " ";
    //cout << '\n';

    cout << accumulate(all(dp), (int)0) % mod << '\n';
}

void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}

signed main() {
    ios::sync_with_stdio(false);
    cout.tie(0);
    cin.tie(0);
    //setIO();

    int t = 1;
    if (tc) {
        cin >> t;
    }

    while (t--) {
        solve();
    }
}

Compilation message (stderr)

Main.cpp: In function 'void setIO(std::string)':
Main.cpp:56:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   56 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:57:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   57 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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