제출 #561328

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
561328		piOOE	밀림 점프 (APIO21_jumps)	C++17	4 / 100	806 ms	31800 KiB

jumps

#include "jumps.h"

#include <bits/stdc++.h>

using namespace std;

#define all(x) begin(x), end(x)

const int logn = 18, N = 200001;

int h[N], jump[logn][N], R[N], L[N], spt[logn][N];

bool okk = true;

int Min(int i, int j) {
    return h[i] < h[j] ? i : j;
}

int Max(int i, int j) {
    return h[i] > h[j] ? i : j;
}

int get_max(int l, int r) {
    if (r <= l) return -1;
    int sz = __lg(r - l);
    return Max(spt[sz][l], spt[sz][r - (1 << sz)]);
}

void init(int n, vector<int> H) {
    for (int i = 0; i < n; ++i) {
        h[i] = H[i];
        okk &= (H[i] == i + 1);
    }
    vector<int> st;
    for (int i = 0; i < n; ++i) {
        while (!st.empty() && h[st.back()] < h[i]) {
            R[st.back()] = i;
            st.pop_back();
        }
        if (st.empty()) {
            L[i] = -1;
        } else {
            L[i] = st.back();
        }
        st.push_back(i);
    }
    for (int i : st) {
        R[i] = n;
    }
    st.clear();
    for (int i = 0; i < n; ++i) {
        jump[0][i] = R[i];
        spt[0][i] = i;
    }
    jump[0][n] = n;
    for (int j = 1; j < logn; ++j) {
        for (int i = 0; i <= n; ++i) {
            jump[j][i] = jump[j - 1][jump[j - 1][i]];
            if (i + (1 << j) <= n) {
                spt[j][i] = Max(spt[j - 1][i], spt[j - 1][i + (1 << (j - 1))]);
            }
        }
    }
}

int minimum_jumps(int A, int B, int C, int D) {
    if (okk) {
        return C - B;
    }
    ++D;
    int mxcd = get_max(C, D);
    int lx = A - 1, rx = C;
    while (lx + 1 < rx) {
        int m = (lx + rx) >> 1;
        if (h[get_max(m, C)] < h[mxcd]) rx = m;
        else lx = m;
    }
    if (rx > B) {
        return -1;
    }
    ++B;
    int i = get_max(rx, B);
    auto get = [](int i, int lx, int rx) {
        int ans = 0;
        for (int j = logn - 1; j > -1; --j) {
            if (jump[j][i] < lx) {
                ans += (1 << j);
                i = jump[j][i];
            }
        }
        if (jump[0][i] >= rx) {
            return -1;
        }
        return ans + 1;
    };
    int ans = INT_MAX;
    int added = 0;
    while (i != -1) {
        int nw = get(i, C, D);
        if (nw != -1) {
            ans = min(ans, added + nw);
        }
        ++added;
        i = L[i];
    }
    return (ans == INT_MAX ? -1 : ans);
}

• Subtask 1: 4 / 4
• Subtask 2: 0 / 8
• Subtask 3: 0 / 13
• Subtask 4: 0 / 12
• Subtask 5: 0 / 23
• Subtask 6: 0 / 21
• Subtask 7: 0 / 19