제출 #1005607

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1005607		TrinhKhanhDung	Trains (BOI24_trains)	C++14	0 / 100	1438 ms	2884 KiB

Main

#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define sz(x) (int)x.size()
#define ALL(v) v.begin(),v.end()
#define MASK(k) (1LL << (k))
#define BIT(x, i) (((x) >> (i)) & 1)
#define oo (ll)1e18
#define INF (ll)1e9
#define MOD (ll)(1e9 + 7)

using namespace std;

template<class T1, class T2>
    bool maximize(T1 &a, T2 b){if(a < b){a = b; return true;} return false;}

template<class T1, class T2>
    bool minimize(T1 &a, T2 b){if(a > b){a = b; return true;} return false;}

template<class T1, class T2>
    void add(T1 &a, T2 b){a += b; if(a >= MOD) a -= MOD;}

template<class T1, class T2>
    void sub(T1 &a, T2 b){a -= b; if(a < 0) a += MOD;}

template<class T>
    void cps(T &v){sort(ALL(v)); v.resize(unique(ALL(v)) - v.begin());}

const int MAX = 1e5 + 10;

int N;
int d[MAX], t[MAX];

void input(){
    cin >> N;
    for(int i=1; i<=N; i++){
        cin >> d[i] >> t[i];
    }
}

namespace subtask2{
    int f[MAX];

    void solve(){
        f[1] = 1;
        for(int i=1; i<=N; i++) if(f[i] && d[i]){
            for(int j=1; j<=t[i]; j++){
                if(i + 1LL * d[i] * j > N) break;
                add(f[i + d[i] * j], f[i]);
            }
        }

        int ans = 0;
        for(int i=1; i<=N; i++){
            add(ans, f[i]);
        }
        cout << ans << '\n';
    }
}

namespace subtask3{
    bool check(){
        for(int i=1; i<=N; i++){
            if(d[i] != 1) return false;
        }
        return true;
    }

    int f[MAX];

    void solve(){
        f[1] = 1;
        for(int i=1; i<=N; i++){
            add(f[i], f[i - 1]);
            int p = min(1LL * N, i + 1LL * d[i] * t[i]);
            add(f[i + 1], 1);
            sub(f[p + 1], 1);
        }

        int ans = 0;
        for(int i=1; i<=N; i++){
            add(ans, f[i]);
        }
        cout << ans << '\n';
    }
}

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0);
//    freopen("netw.inp", "r", stdin);
//    freopen("netw.out", "w", stdout);

    input();

    if(subtask3::check()) return subtask3::solve(), 0;
    return subtask2::solve(), 0;

    return 0;
}

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