Submission #766053

#	Time	Username	Problem	Language	Result	Execution time	Memory
766053		sysia	Railway Trip 2 (JOI22_ho_t4)	C++17	100 / 100	834 ms	97776 KiB

Main

//Sylwia Sapkowska
#include <bits/stdc++.h>
#pragma GCC optimize("O3", "unroll-loops")
using namespace std;

void __print(int x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << "'" << x << "'";}
void __print(const char *x) {cerr << '"' << x << '"';}
void __print(const string &x) {cerr << '"' << x << '"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ", "; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? ", " : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifdef LOCAL
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif

#define int long long
typedef pair<int, int> T;
const int oo = 1e18, oo2 = 1e9+7, K = 20;
const int mod = 998244353;

struct TreeMin{
    vector<int>tab;
    int size = 1;

    void init(int n){
        while (size < n) size*=2;
        tab.assign(2*size, oo);
    }

    void update(int x, int v){
        x += size;
        tab[x] = min(tab[x], v);
        while (x){
            x/=2;
            tab[x] = min(tab[2*x], tab[2*x+1]);
        }
    }

    int query(int l, int r){
        int ans = oo;
        for (l += size-1, r += size+1; r-l>1; l/=2, r/=2){
            if (!(l&1)) ans = min(ans, tab[l+1]);
            if (r&1) ans = min(ans, tab[r-1]);
        }
        return ans;
    }
};

struct TreeMax{
    vector<int>tab;
    int size = 1;

    void init(int n){
        while (size < n) size*=2;
        tab.assign(2*size, -oo);
    }

    void update(int x, int v){
        x += size;
        tab[x] = max(tab[x], v);
        while (x){
            x/=2;
            tab[x] = max(tab[2*x], tab[2*x+1]);
        }
    }

    int query(int l, int r){
        int ans = -oo;
        for (l += size-1, r += size+1; r-l>1; l/=2, r/=2){
            if (!(l&1)) ans = max(ans, tab[l+1]);
            if (r&1) ans = max(ans, tab[r-1]);
        }
        return ans;
    }
};

void solve(){
    int n, k; cin >> n >> k;
    int m; cin >> m;
    vector<T>where(m);
    for (auto &[x, y]: where) cin >> x >> y;
    multiset<int>s;
    vector<T>sweep;
    //left to right
    for (int i = 0; i<m; i++){
        if (where[i].first < where[i].second){
            sweep.emplace_back(where[i].first, where[i].second);
            sweep.emplace_back(min(where[i].first + k, where[i].second), -where[i].second);
        }
    }
    sort(sweep.begin(), sweep.end());
    debug(sweep);
    vector<int>right(n+1);
    int ptr = -1;
    for (int i = 1; i<=n; i++){
        while (ptr + 1 < (int)sweep.size() && sweep[ptr+1].first <= i){
            ptr++;
            if (sweep[ptr].second > 0) s.insert(sweep[ptr].second);
            else s.erase(s.find(-sweep[ptr].second));
        }
        right[i] = (!s.empty() ? *s.rbegin() : i);
    }
    debug(right);

    //right to left
    s.clear(); sweep.clear();
    for (int i = 0; i<m; i++){
        if (where[i].first > where[i].second){
            sweep.emplace_back(where[i].first, where[i].second);
            sweep.emplace_back(max(where[i].first - k, where[i].second), -where[i].second);
        }
    }
    sort(sweep.begin(), sweep.end());
    debug(sweep);
    vector<int>left(n+1);
    ptr = (int)sweep.size();
    for (int i = n; i>=1; i--){
        while (ptr - 1 >= 0 && sweep[ptr-1].first >= i){
            ptr--;
            if (sweep[ptr].second > 0) s.insert(sweep[ptr].second);
            else s.erase(s.find(-sweep[ptr].second));
        }
        left[i] = (!s.empty() ? *s.begin() : i);
    }
    debug(left);
    vector<TreeMin>L(K);
    vector<TreeMax>R(K);
    for (int i = 0; i<K; i++){
        L[i].init(n+2);
        R[i].init(n+2);
    }
    for (int i = 1; i<=n; i++) {
        L[0].update(i, left[i]);
        R[0].update(i, right[i]);
    }
    for (int j = 1; j<K; j++){
        debug(j);
        for (int i = 1; i<=n; i++){
            int ll = L[j-1].query(i, i);
            int rr = R[j-1].query(i, i);
            L[j].update(i, L[j-1].query(ll, rr));
            R[j].update(i, R[j-1].query(ll, rr));
            debug(i, L[j-1].query(ll, rr), R[j-1].query(ll, rr));
        }
    }
    int q; cin >> q;
    while (q--){
        int a, b; cin >> a >> b;
        int ans = 0;
        int ll = a, rr = a;
        bool any = 0;
        for (int i = K-1; i>=0; i--){
            int newL = L[i].query(ll, rr);
            int newR = R[i].query(ll, rr);
            if (b >= newL && b <= newR){
                any = 1;
                ;
            } else {
                ans += (1<<i);
                ll = newL;
                rr = newR;
            }
        }
        if (!any) cout << "-1\n";
        else  cout << ans+1 << "\n";
    }
}

int32_t main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    int t = 1;
    //cin >> t;
    while (t--) solve();

    return 0;
}

• Subtask 1: 8 / 8
• Subtask 2: 8 / 8
• Subtask 3: 11 / 11
• Subtask 4: 25 / 25
• Subtask 5: 35 / 35
• Subtask 6: 13 / 13