Submission #1010566

#	Time	Username	Problem	Language	Result	Execution time	Memory
1010566		Beerus13	Trains (BOI24_trains)	C++14	100 / 100	214 ms	130648 KiB

Main

#include<bits/stdc++.h>
using namespace std;
#define FOR(i, a, b)  for(int i = (a), _b = (b); i <= _b; ++i)
#define FORD(i, b, a) for(int i = (b), _a = (a); i >= _a; --i)
#define REP(i, a, b)  for(int i = (a), _b = (b); i < _b;  ++i)
#define REPD(i, b, a) for(int i = (b), _a = (a); i > _a;  --i)
#define MASK(i) (1LL << (i))
#define BIT(mask, i) (((mask) >> (i)) & 1)
#define __builtin_popcount __builtin_popcountll
#define all(val) val.begin(), val.end()
#define ll long long
#define ull unsigned long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define fi first
#define se second

mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll Rand(ll l, ll r) {return l + rng() % (r - l + 1);}

template<class X, class Y>
    bool minimize(X &x, const Y &y) {
        if (x > y) {
            x = y;
            return true;
        } else return false;
    }
template<class X, class Y>
    bool maximize(X &x, const Y &y) {
        if (x < y) {
            x = y;
            return true;
        } else return false;
    }
template<class T>
    T Abs(const T &x) {
        return (x < 0 ? -x : x);
    }

const int N = 1e5 + 5;
const int sqr = 320;
const int mod = 1e9 + 7;

void add(int &a, const int &b) {
    a += b;
    if(a >= mod) a -= mod;
    if(a < 0) a += mod;
}

int mul(const int &a, const int &b) {
    return 1ll * a * b % mod;
}

int n, d[N], x[N];
int dp[N], f[N][sqr + 5];

int check1, check2;

void sub2() {
    if(n > 1e4) return;
    dp[1] = 1;
    int res = 0;
    FOR(i, 1, n) if(x[i] && d[i]) {
        FOR(j, 1, x[i]) {
            if(i + j * d[i] > n) break;
            add(dp[i + j * d[i]], dp[i]);
        }
    }
    FOR(i, 1, n) add(res, dp[i]);
    check1 = res;
    cout << res << '\n';
    exit(0);
}

void sub5() {
    dp[1] = 1;
    int res = 0;
    FOR(i, 1, n) {
        FOR(k, 1, sqr) {
            if(i >= k) add(f[i][k], f[i - k][k]);
            add(dp[i], f[i][k]);
        }

        if(d[i] == 0 || x[i] == 0) continue;

        if(d[i] > sqr) {
            FOR(j, 1, x[i]) {
                if(i + j * d[i] > n) break;
                add(dp[i + j * d[i]], dp[i]);
            }
        }
        else {
            add(f[i][d[i]], dp[i]);
            ll mx = 1ll * d[i] * (x[i] + 1);
            if(i + mx <= n) add(f[i + mx][d[i]], -dp[i]);
        }
    }
    FOR(i, 1, n) add(res, dp[i]);
    check2 = res;
    cout << res << '\n';
    exit(0);
}

void sinhtest() {
    int ntests = 10;
    while(ntests--) {
        n = Rand(1, 1e3);
        FOR(i, 1, n) {
            d[i] = Rand(0, 1e9);
            x[i] = Rand(0, 1e9);
        }
        memset(dp, 0, sizeof(dp));
        FOR(i, 1, n) memset(f[i], 0, sizeof(f[i]));
        sub2();
        memset(dp, 0, sizeof(dp));
        sub5();
        if(check1 == check2) cout << "CORRECT\n";
        else {
            cout << "INCORRECT\n";
            cout << n << '\n';
            FOR(i, 1, n) cout << d[i] << ' ' << x[i] << '\n';
            return;
        }
    }
}

void process() {
    cin >> n;
    FOR(i, 1, n) cin >> d[i] >> x[i];
    sub2();
    sub5();
}

signed main() {
    if(fopen("test.inp","r")) {
        freopen("test.inp","r",stdin);
        freopen("test.out","w",stdout);
    }
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    int ntests = 1;
    // cin >> ntests;
    while(ntests--) process();
    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:136:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  136 |         freopen("test.inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
Main.cpp:137:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  137 |         freopen("test.out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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