Submission #769168

#	Time	Username	Problem	Language	Result	Execution time	Memory
769168		stevancv	Rainforest Jumps (APIO21_jumps)	C++14	81 / 100	4074 ms	63116 KiB

jumps

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define sp ' '
#define en '\n'
#define smin(a, b) a = min(a, b)
#define smax(a, b) a = max(a, b)
using namespace std;
const int N = 2e5 + 2;
const int inf = 2e9;
int low[N][18], high[N][18], lef[N], rig[N], inv[N], logs[N], a[N], NN, S1;
pair<int, int> rmq[N][18];
auto Query(int l, int r) {
    int o = logs[r - l + 1];
    return max(rmq[l][o], rmq[r - (1 << o) + 1][o]);
}
void init(int n, vector<int> A) {
    NN = n;
    S1 = 1;
    for (int i = 1; i <= n; i++) {
        a[i] = A[i - 1];
        S1 &= (a[i] == i);
        rmq[i][0] = {a[i], i};
        inv[a[i]] = i;
    }
    for (int j = 1; j < 18; j++) {
        for (int i = 1; i <= n - (1 << j) + 1; i++) {
            rmq[i][j] = max(rmq[i][j - 1], rmq[i + (1 << (j - 1))][j - 1]);
        }
    }
    int z = 0;
    for (int i = 1; i <= n; i++) {
        if (i == (1 << (z + 1))) z += 1;
        logs[i] = z;
    }
    stack<int> s;
    for (int i = 1; i <= n; i++) {
        while (!s.empty() && a[s.top()] < a[i]) s.pop();
        if (!s.empty()) lef[i] = s.top();
        s.push(i);
    }
    while (!s.empty()) s.pop();
    for (int i = n; i >= 1; i--) {
        while (!s.empty() && a[s.top()] < a[i]) s.pop();
        if (!s.empty()) rig[i] = s.top();
        s.push(i);
    }
    for (int i = 1; i <= n; i++) {
        if (a[lef[i]] > a[rig[i]]) {
            high[i][0] = lef[i];
            low[i][0] = rig[i];
        }
        else {
            high[i][0] = rig[i];
            low[i][0] = lef[i];
        }
    }
    for (int ii = n; ii >= 1; ii--) {
        int i = inv[ii];
        for (int j = 1; j < 18; j++) {
            high[i][j] = high[high[i][j - 1]][j - 1];
            low[i][j] = low[low[i][j - 1]][j - 1];
        }
    }
}
int Dist(int p, int q) {
    int d = 0;
    for (int i = 17; i >= 0; i--) {
        if (high[p][i] && a[high[p][i]] <= a[q]) {
            d += (1 << i);
            p = high[p][i];
        }
    }
    for (int i = 17; i >= 0; i--) {
        if (low[p][i] && a[low[p][i]] <= a[q]) {
            d += (1 << i);
            p = low[p][i];
        }
    }
    if (p != q) return -1;
    return d;
}
int minimum_jumps(int a, int b, int c, int d) {
    a += 1; b += 1; c += 1; d += 1;
    if (S1) return c - b;
    if (c != d) {
        queue<int> q;
        vector<int> dist(NN + 1, inf);
        for (int i = a; i <= b; i++) {
            q.push(i);
            dist[i] = 0;
        }
        while (!q.empty()) {
            int i = q.front();
            q.pop();
            if (lef[i] > 0 && dist[lef[i]] > dist[i] + 1) {
                q.push(lef[i]);
                dist[lef[i]] = dist[i] + 1;
            }
            if (rig[i] > 0 && dist[rig[i]] > dist[i] + 1) {
                q.push(rig[i]);
                dist[rig[i]] = dist[i] + 1;
            }
        }
        int ans = inf;
        for (int i = c; i <= d; i++) smin(ans, dist[i]);
        if (ans == inf) ans = -1;
        return ans;
    }
    int koji = Query(c, d).first;
    int l = a, r = b, gde = 0;
    while (l <= r) {
        int mid = l + r >> 1;
        if (Query(mid, b).first < koji) {
            gde = mid;
            r = mid - 1;
        }
        else l = mid + 1;
    }
    if (gde == 0) return -1;
    gde = Query(gde, b).second;
      l = c, r = d;
    int ret = -1;
    while (l <= r) {
        int mid = l + r >> 1;
        int x = Dist(gde, Query(c, mid).second);
        if (x != -1) {
            ret = x;
            r = mid - 1;
        }
        else l = mid + 1;
    }
    return ret;
}

Compilation message (stderr)

jumps.cpp: In function 'int minimum_jumps(int, int, int, int)':
jumps.cpp:113:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  113 |         int mid = l + r >> 1;
      |                   ~~^~~
jumps.cpp:125:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  125 |         int mid = 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: 0 / 19