Submission #1115909

#	Time	Username	Problem	Language	Result	Execution time	Memory
1115909		nathan4690	Toll (BOI17_toll)	C++17	100 / 100	142 ms	14408 KiB

toll

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define el cout << '\n'
#define f1(i,n) for(int i=1;i<=n;i++)
#define __file_name ""
using namespace std;
const ll maxn = 5e4+5, inf=1e18;

struct Matrix{
    int r, c;
    vector<vector<ll>> data;
    Matrix(){};
    Matrix(int r, int c): r(r), c(c), data(r, vector<ll>(c, 1e9)){};
    Matrix(vector<vector<ll>> a): r(a.size()), c(a.empty() ? 0 : a[0].size()), data(a){};
    Matrix operator*(const Matrix &rhs) const{
        assert(c == rhs.r);
        Matrix res(r, rhs.c);
//        cout << (*this) << "TIMES\n" << rhs;el;
        for(int i=0;i<r;i++){
            for(int j=0;j<rhs.c;j++){
                for(int k=0;k<c;k++){
                    res.data[i][j] = min(res.data[i][j], data[i][k] + rhs.data[k][j]);
                }
            }
        }
        return res;
    }
    Matrix operator^(const long long &e) const{
        assert(r == c);
        Matrix res(r,c), base(*this);
        for(int i=0;i<r;i++) res.data[i][i] = 1;
        long long _e = e;
        while(_e){
            if(_e & 1) res = res * base;
            base = base * base;
            _e >>= 1;
        }
        return res;
    }
    int get(int _r, int _c){
        // 1-indexed
        return data[_r-1][_c-1];
    }
    friend ostream& operator<<(ostream& ouf, const Matrix &rhs){
        for(int i=0;i<rhs.r;i++){
            for(int j=0;j<rhs.c;j++){
                ouf << rhs.data[i][j] << ' ';
            }
            ouf << '\n';
        }
        return ouf;
    }
};

Matrix st[4*maxn];

int k, n, m, o, id[maxn];

void build(int idx, int l, int r, bool flag = true){
    if(l == r){
        if(flag){
            id[l] = idx;
            st[idx] = Matrix(k, k);
            // f1(i,k) f1(j,k) st[idx].data[i-1][j-1] = 1e9;
        }
        return;
    }
    int mid = (l + r) / 2;
    build(idx*2, l, mid, flag);
    build(idx*2+1, mid+1, r, flag);
    st[idx] = st[idx*2] * st[idx*2+1];
}

Matrix get(int idx, int l, int r, int u, int v){
    if(v < l || r < u) {
        Matrix res(k, k);
        f1(i, k) f1(j, k){
            if(i == j) res.data[i-1][j-1] = 0;
        }
        return res;
    }
    if(u <= l && r <= v) return st[idx];
    int mid = (l + r) / 2;
    return get(idx*2, l, mid, u, v) * get(idx*2+1, mid+1, r, u, v);
}

int main(){
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);

    if(fopen(__file_name ".inp", "r")){
        freopen(__file_name ".inp","r",stdin);
        freopen(__file_name ".out","w",stdout);
    }
    // code here
    cin >> k >> n >> m >> o;
    build(1, 0, n / k);
    f1(i,m){
        int a, b, t;
        cin >> a >> b >> t;
        int bl = a/k;
//        cout << id[bl] << ' ' << a % k << ' ' << b % k << ' ' << t;el;
        st[id[bl]].data[a % k][b % k] = min((int)st[id[bl]].data[a % k][b % k], t);
    }
    build(1, 0, n / k, false);
    // cout << "BUILD COMPLETE\n\n";
//    for(int i=0;i<=n/k;i++) cout << st[id[i]] << "\n\n";
    while(o--){
        int a, b; cin >> a >> b;
        if(a / k == b / k){
            if(a == b) cout << 0;
            else cout << -1;
            el;
            continue;
        }
        int bla = a / k, blb = b / k;
        Matrix res = Matrix(1, k);
        for(int i=0;i<k;i++) res.data[0][i] = 1e9;
        res.data[0][a % k] = 0;
//        for(int b=bla;b<blb;b++) {
//            res = res * st[id[b]];
//            cout << b << ' ' << id[b];el;
//            for(int i=0;i<k;i++) cout << res.data[0][i] << ' ';el;
//        }
//        for(int i=0;i<k;i++) cout << get(1,0,n/k,bla,blb-1).data[0][i] << ' ';el;
        res = res * get(1,0,n/k,bla,blb-1);
//        for(int i=0;i<k;i++) cout << get(1,0,n/k,bla,blb-1).data[0][i] << ' ';el;
        if(res.data[0][b % k] >= 1e9) cout << -1;
        else cout << res.data[0][b % k];
        el;
    }
    return 0;
}

Compilation message (stderr)

toll.cpp: In function 'int main()':
toll.cpp:92:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   92 |         freopen(__file_name ".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
toll.cpp:93:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   93 |         freopen(__file_name ".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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