Submission #858358

#	Time	Username	Problem	Language	Result	Execution time	Memory
858358		chanhchuong123	Rainforest Jumps (APIO21_jumps)	C++14	100 / 100	816 ms	45416 KiB

jumps

#include <bits/stdc++.h>
using namespace std;
#define task ""

const int MAX = 200020;
int n, q;
int H[MAX];
stack<int> st;
int dp[18][MAX], rg[18][MAX], hi[18][MAX];
#define combine(x, y) (H[(x)] < H[(y)] ? y : x)

void init(int N, vector<int> _H) {
    n = N;
    for (int i = 0; i < n; ++i) {
        H[i + 1] = _H[i];
    }
    H[0] = H[n + 1] = n + 1; st.push(0);
    for (int i = 1; i <= n; ++i) {
        while (H[st.top()] < H[i]) st.pop();
        hi[0][i] = st.top(); st.push(i);
    }
    st.push(n + 1); rg[0][0] = rg[0][n + 1] = n + 1;
    for (int i = n; i >= 1; --i) {
        while (H[st.top()] < H[i]) st.pop();
        rg[0][i] = st.top(); st.push(i);
    }

    for (int i = 1; i <= n; ++i) {
        dp[0][i] = i;
        hi[0][i] = combine(hi[0][i], rg[0][i]);
    }
    for (int j = 1; j <= 17; ++j) {
        for (int i = 0; i <= n + 1; ++i) {
            hi[j][i] = hi[j - 1][hi[j - 1][i]];
            rg[j][i] = rg[j - 1][rg[j - 1][i]];
            if (i + (1 << j) - 1 <= n) dp[j][i] = combine(dp[j - 1][i], dp[j - 1][i + (1 << j - 1)]);
        }
    }
}

int getMax(int l, int r) {
    int k = 31 - __builtin_clz(r - l + 1);
    return combine(dp[k][l], dp[k][r - (1 << k) + 1]);
}

bool in(int x, int C, int D) {
    return C <= x && x <= D;
}

int minimum_jumps(int A, int B, int C, int D) {
    ++A;
    ++B;
    ++C;
    ++D;
    int CD = getMax(C, D);
    int BC = getMax(B, C - 1);
    if (H[BC] > H[CD]) return -1;
    int l = A, r = B;
    while (l <= r) {
        int m = l + r >> 1;
        if (H[getMax(m, B)] < H[CD]) r = m - 1; else l = m + 1;
    }
    int st = getMax(l, B);
    if (in(rg[0][st], C, D)) return 1;
    int res = 0;
    for (int j = 17; j >= 0; --j) if (rg[0][hi[j][st]] < C) {
        st = hi[j][st];
        res += 1 << j;
    }
    int nt = hi[0][st];
    if (rg[0][nt] <= D) {
        st = nt; ++res;
        if (in(rg[0][nt], C, D)) return res + 1;
    }
    for (int j = 17; j >= 0; --j) if (rg[j][st] < C) {
        st = rg[j][st];
        res += 1 << j;
    }
    return res + 1;
}

Compilation message (stderr)

jumps.cpp: In function 'void init(int, std::vector<int>)':
jumps.cpp:36:95: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   36 |             if (i + (1 << j) - 1 <= n) dp[j][i] = combine(dp[j - 1][i], dp[j - 1][i + (1 << j - 1)]);
      |                                                                                             ~~^~~
jumps.cpp:10:36: note: in definition of macro 'combine'
   10 | #define combine(x, y) (H[(x)] < H[(y)] ? y : x)
      |                                    ^
jumps.cpp:36:95: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   36 |             if (i + (1 << j) - 1 <= n) dp[j][i] = combine(dp[j - 1][i], dp[j - 1][i + (1 << j - 1)]);
      |                                                                                             ~~^~~
jumps.cpp:10:42: note: in definition of macro 'combine'
   10 | #define combine(x, y) (H[(x)] < H[(y)] ? y : x)
      |                                          ^
jumps.cpp: In function 'int minimum_jumps(int, int, int, int)':
jumps.cpp:60:19: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   60 |         int m = l + r >> 1;
      |                 ~~^~~

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