Submission #753626

#	Time	Username	Problem	Language	Result	Execution time	Memory
753626		hafo	Toll (BOI17_toll)	C++14	100 / 100	126 ms	157800 KiB

toll

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned ll
#define pb push_back
#define pa pair<int, int>
#define pall pair<ll, int>
#define fi first
#define se second
#define TASK "test"
#define Size(x) (int) x.size()
#define all(x) x.begin(), x.end()
using namespace std;

template<typename T1, typename T2> bool mini (T1 &a, T2 b) {if(a > b) a = b; else return 0; return 1;}
template<typename T1, typename T2> bool maxi (T1 &a, T2 b) {if(a < b) a = b; else return 0; return 1;}

const int MOD = 1e9 + 7;
const int LOG = 16;
const int maxn = 5e4 + 7;
const ll oo = 1e17 + 69;

int k, n, q, m, u, v, w;

struct matrix{
    ll a[5][5];

    void init() {
        for(int i = 0; i < k; i++)
            for(int j = 0; j < k; j++) a[i][j] = oo;
    }

    friend matrix operator * (matrix a, matrix b) {
        matrix c;
        c.init();
        for(int i = 0; i < k; i++) {
            for(int j = 0; j < k; j++) {
                for(int h = 0; h < k; h++) {
                    mini(c.a[i][j], a.a[i][h] + b.a[h][j]);
                }
            }
        }
        return c;
    }
};

matrix st[LOG][maxn];

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    //freopen(TASK".inp", "r", stdin);
    //freopen(TASK".out", "w", stdout);

    cin>>k>>n>>m>>q;
    for(int i = 0; i < LOG; i++)
        for(int j = 0; j < n / k; j++) st[i][j].init();
    while(m--) {
        cin>>u>>v>>w;
        st[0][u / k].a[u % k][v % k] = w;
    }

    for(int i = 1; i < LOG; i++) {
        for(int u = 0; u + (1 << i) - 1 <= (n - 1) / k; u++) {
            st[i][u] = st[i - 1][u] * st[i - 1][u + (1 << (i - 1))];
        }
    }

    while(q--) {
        cin>>u>>v;
        if(u / k >= v / k) {
            cout<<-1<<"\n";
            continue;
        }
        matrix ans;
        for(int i = 0; i < k; i++)
            for(int j = 0; j < k; j++) ans.a[i][j] = (i == j ? 0:oo);
        int len = v / k - u / k;
        int s = u / k;
        for(int i = 0; i < LOG; i++)
        if((len >> i) & 1) {
            matrix cur;
            cur.init();
            cur = ans * st[i][s];
            ans = cur;
            s += (1 << i);
        }
        if(ans.a[u % k][v % k] == oo) cout<<-1;
        else cout<<ans.a[u % k][v % k];
        cout<<"\n";
    }
    return 0;
}

• Subtask 1: 7 / 7
• Subtask 2: 10 / 10
• Subtask 3: 8 / 8
• Subtask 4: 31 / 31
• Subtask 5: 44 / 44