Submission #1194572

#	Time	Username	Problem	Language	Result	Execution time	Memory
1194572		biank	Railway Trip 2 (JOI22_ho_t4)	C++20	27 / 100	2095 ms	3396 KiB

Main

#include <bits/stdc++.h>

using namespace std;

#define forn(i,n) for(int i=0;i<int(n);i++)
#define forsn(i,s,n) for(int i=int(s);i<int(n);i++)
#define dforn(i,n) for(int i=int(n)-1;i>=0;i--)
#define dforsn(i,s,n) for(int i=int(n)-1;i>=int(s);i--)
#define fst first
#define snd second
#define pb push_back
#define eb emplace_back
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()

typedef long long ll;
typedef vector<ll> vll;
typedef vector<int> vi;
typedef pair<int,int> ii;

const int SZ = 1 << 17;
const int INF = 1e9;

int maxi[2 * SZ], mini[2 * SZ];

template<typename T>
void chmin(T &x, T v) {
    if (x > v) x = v;
}

template<typename T>
void chmax(T &x, T v) {
    if (x < v) x = v;
}

void update(int l, int r, int v) {
    //cerr << l << ' ' << r << ' '  << v << '\n';
    for (l += SZ, r += SZ; l < r; l /= 2, r /= 2) {
        if (l & 1) {
            chmax(maxi[l], v);
            chmin(mini[l], v);
            l++;
        }
        if (r & 1) {
            --r;
            chmax(maxi[r], v);
            chmin(mini[r], v);
        }
    }
} 

int queryMax(int i) {
    int res = maxi[i += SZ];
    while (i /= 2) chmax(res, maxi[i]);
    return res;
}

int queryMin(int i) {
    int res = mini[i += SZ];
    while (i /= 2) chmin(res, mini[i]);
    return res;
}

/*struct Node {
    int value, index;
    bool active = false;
};

Node operator+(Node lhs, Node rhs) {
    if (!lhs.active) return rhs;
    if (!rhs.active) return lhs;
    if (lhs.value < rhs.value) return lhs;
    return rhs;
}

Node st[2 * SZ];
int lazy[2 * SZ];

void pass(int u) {
    if (lazy[u] == INF) return;
    if (u < SZ) {
        lazy[2 * u] = min(lazy[2 * u], lazy[u]);
        lazy[2 * u + 1] = min(lazy[2 * u + 1], lazy[u]);
    }
    st[u].value = min(st[u].value, lazy[u]);
    lazy[u] = INF;
}

void updateRange(int s, int e, int v, int l = 0, int r = SZ, int u = 1) {
    pass(u);
    if (e <= l || r <= s) {
        return;
    } 
    if (s <= l && r <= e) {
        lazy[u] = v;
        return pass(u);
    }
    int m = (l + r) / 2;
    updateRange(s, e, v, l, m, 2 * u);
    updateRange(s, e, v, m, r, 2 * u + 1);
    st[u] = st[2 * u] + st[2 * u + 1];
}

void deactivate(int p, int l = 0, int r = SZ, int u = 1) {
    pass(u);
    if (u >= SZ) {
        st[u].active = false;
        return;
    }
    int m = (l + r) / 2;
    if (p < m) deactivate(p, l, m, 2 * u);
    else deactivate(p, m, r, 2 * u + 1);
    pass(2 * u), pass(2 * u + 1);
    st[u] = st[2 * u] + st[2 * u + 1];
}*/

int askMin(int l, int r) {
    int res = INF;
    for (l += SZ, r += SZ; l < r; l /= 2, r /= 2) {
        if (l & 1) chmin(res, mini[l++]);
        if (r & 1) chmin(res, mini[--r]);
    }
    return res;
}

int askMax(int l, int r) {
    int res = -INF;
    for (l += SZ, r += SZ; l < r; l /= 2, r /= 2) {
        if (l & 1) chmax(res, maxi[l++]);
        if (r & 1) chmax(res, maxi[--r]);
    }
    return res;
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    
    int n, k, m;
    cin >> n >> k >> m;
    forn(i, 2 * SZ) mini[i] = INF, maxi[i] = -INF;
    forn(i, n) update(i, i + 1, i);
    forn(i, m) {
        int a, b;
        cin >> a >> b;
        --a, --b;
        if (a < b) {
            update(a, min(a + k, b), b);
        } else {
            update(max(a - k + 1, b + 1), a + 1, b);
        }
    }
    vi left(n), right(n);
    forn(i, n) left[i] = queryMin(i);
    forn(i, n) right[i] = queryMax(i);
    forn(i, 2 * SZ) mini[i] = INF, maxi[i] = -INF;
    forn(i, n) mini[i + SZ] = left[i], maxi[i + SZ] = right[i];
    dforsn(i, 1, SZ) {
        mini[i] = min(mini[2 * i], mini[2 * i + 1]);
        maxi[i] = max(maxi[2 * i], maxi[2 * i + 1]);
    }
    //forn(i, n) cerr << left[i] << ' ' << right[i] << '\n';
    int q;
    cin >> q;
    forn(_, q) {
        int s, t;
        cin >> s >> t;
        --s, --t;
        int dist = 1;
        int l = left[s], r = right[s];
        bool flag = true;
        while (l > t || r < t) {
            //cerr << l << ' ' << r << '\n';
            int newL = askMin(l, r + 1);
            int newR = askMax(l, r + 1);
            if (l == newL && r == newR) {
                flag = false;
                break;
            }
            dist++, l = newL, r = newR;
        }
        if (flag) cout << dist << '\n';
        else cout << "-1\n";
        
    }
    
    return 0;
}

• Subtask 1: 8 / 8
• Subtask 2: 8 / 8
• Subtask 3: 11 / 11
• Subtask 4: 0 / 25
• Subtask 5: 0 / 35
• Subtask 6: 0 / 13