Submission #857384

#	Time	Username	Problem	Language	Result	Execution time	Memory
857384		chanhchuong123	Rainforest Jumps (APIO21_jumps)	C++14	4 / 100	959 ms	45880 KiB

jumps

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

const int INF = 1e9 + 7;
const int MAX = 200020;
stack<int> st;
int nTree, nQuery, H[MAX];
int lf[18][MAX], rg[18][MAX], dp[18][MAX];
int combine(int x, int y) { return H[x] >= H[y] ? x : y; }

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]);
}

int jumpRg(int u, int C, int D) {
    int res = 1;
    for (int j = 17; j >= 0; --j) if (rg[j][u] != -1) {
        if (rg[j][u] < C) {
            u = rg[j][u];
            res += 1 << j;
        }
    }
    u = rg[0][u];
    if (C <= u && u <= D) return res; return INF;
}

int jumpRg(int u, int f, int C, int D) {
    return jumpRg(u, f, f) + jumpRg(f, C, D);
}

int jumpLf(int u, int v) {
    int res = 1;
    for (int j = 17; j >= 0; --j) if (lf[j][u] != -1) {
        if (lf[j][u] > v) {
            u = lf[j][u];
            res += 1 << j;
        }
    }
    u = lf[0][u];
    if (u == v) return res; return INF;
}

int minimum_jumps(int A, int B, int C, int D) {
    if (B + 1 == C) {
        int ans = jumpRg(B, C, D);
        if (ans == INF) ans = -1;
        return ans;
    }
    int f = getMax(B + 1, C - 1), ans = jumpRg(B, C, D);
    {
        int l = A - 1, r = B;
        while (r - l > 1) {
            int mid = l + r >> 1;
            if (H[getMax(mid, B)] < H[f]) r = mid; else l = mid;
        }
        int u = getMax(r, B);
        if (H[u] < H[f]) ans = min(ans, jumpRg(u, f, C, D));
        if (A <= r - 1) ans = min(ans, jumpRg(r - 1, C, D));
    }
    if (A - 1 >= 1) {
        int l = 0, r = A - 1;
        while (r - l > 1) {
            int mid = l + r >> 1;
            if (H[getMax(mid, A - 1)] < H[f]) r = mid; else l = mid;
        }
        int g = getMax(r, A - 1);
        if (H[g] < H[f]) {
            int l = A, r = B + 1;
            while (r - l > 1) {
                int mid = l + r >> 1;
                if (H[getMax(A, mid)] < H[g]) l = mid; else r = mid;
            }
            int u = getMax(A, l);
            if (H[u] < H[g]) {
                int res = jumpLf(u, g) + jumpRg(g, C, D);
                ans = min(ans, res);
            }
        }
        if (g > 1) {
            --g;
            if (H[g] > H[f]) {
                int l = A, r = B + 1;
                while (r - l > 1) {
                    int mid = l + r >> 1;
                    if (H[getMax(A, mid)] < H[g]) l = mid; else r = mid;
                }
                int u = getMax(A, l);
                if (H[u] < H[g]) {
                    ans = min(ans, jumpLf(u, g) + jumpRg(g, C, D));
                }
            }
        }
    }
    if (ans == INF) ans = -1;
    return ans;
}

void init(int N, vector<int> _H) {
    nTree = N;
    for (int i = 0; i < nTree; ++i) {
        H[i] = _H[i];
        dp[0][i] = H[i];
    }
    st = stack<int> {};
    for (int i = 0; i <= nTree - 1; ++i) {
        while (st.size() && H[st.top()] < H[i]) st.pop();
        lf[0][i] = st.size() ? st.top() : -1; st.push(i);
    }
    st = stack<int> {};
    for (int i = nTree - 1; i >= 0; --i) {
        while (st.size() && H[st.top()] < H[i]) st.pop();
        rg[0][i] = st.size() ? st.top() : -1; st.push(i);
    }

    for (int j = 1; j <= 17; ++j) {
        for (int i = 0; i < nTree; ++i) {
            if (lf[j - 1][i] != -1) lf[j][i] = lf[j - 1][lf[j - 1][i]]; else lf[j][i] = -1;
            if (rg[j - 1][i] != -1) rg[j][i] = rg[j - 1][rg[j - 1][i]]; else rg[j][i] = -1;
        }
    }
    for (int j = 1; (1 << j) <= nTree; ++j) {
        for (int i = 0; i + (1 << j) <= nTree; ++i)
            dp[j][i] = combine(dp[j - 1][i], dp[j - 1][i + (1 << j - 1)]);
    }
}
//
//int main() {
//	ios_base::sync_with_stdio(false); cin.tie(nullptr);
//
//	if (fopen(task".inp", "r")) {
//		freopen(task".inp", "r", stdin);
//		freopen(task".out", "w", stdout);
//	}
//
//    cin >> nTree >> nQuery;
//    for (int i = 0; i < nTree; ++i) {
//        cin >> H[i]; dp[0][i] = i;
//    }
//
//    st = stack<int> {};
//    for (int i = 0; i <= nTree - 1; ++i) {
//        while (st.size() && H[st.top()] < H[i]) st.pop();
//        lf[0][i] = st.size() ? st.top() : -1; st.push(i);
//    }
//    st = stack<int> {};
//    for (int i = nTree - 1; i >= 0; --i) {
//        while (st.size() && H[st.top()] < H[i]) st.pop();
//        rg[0][i] = st.size() ? st.top() : -1; st.push(i);
//    }
//
//    for (int j = 1; j <= 17; ++j) {
//        for (int i = 0; i < nTree; ++i) {
//            if (lf[j - 1][i] != -1) lf[j][i] = lf[j - 1][lf[j - 1][i]]; else lf[j][i] = -1;
//            if (rg[j - 1][i] != -1) rg[j][i] = rg[j - 1][rg[j - 1][i]]; else rg[j][i] = -1;
//        }
//    }
//    for (int j = 1; (1 << j) <= nTree; ++j) {
//        for (int i = 0; i + (1 << j) <= nTree; ++i)
//            dp[j][i] = combine(dp[j - 1][i], dp[j - 1][i + (1 << j - 1)]);
//    }
//    while (nQuery--) {
//        int A, B, C, D; cin >> A >> B >> C >> D;
//        cout << minimum_jumps(A, B, C, D) << '\n';
//    }
//	return 0;
//}

/*
7 3
3 2 1 6 4 5 7
4 4 6 6
1 3 5 6
0 1 2 2
*/

Compilation message (stderr)

jumps.cpp: In function 'int jumpRg(int, int, int)':
jumps.cpp:27:5: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   27 |     if (C <= u && u <= D) return res; return INF;
      |     ^~
jumps.cpp:27:39: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   27 |     if (C <= u && u <= D) return res; return INF;
      |                                       ^~~~~~
jumps.cpp: In function 'int jumpLf(int, int)':
jumps.cpp:43:5: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   43 |     if (u == v) return res; return INF;
      |     ^~
jumps.cpp:43:29: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   43 |     if (u == v) return res; return INF;
      |                             ^~~~~~
jumps.cpp: In function 'int minimum_jumps(int, int, int, int)':
jumps.cpp:56:25: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   56 |             int mid = l + r >> 1;
      |                       ~~^~~
jumps.cpp:66:25: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   66 |             int mid = l + r >> 1;
      |                       ~~^~~
jumps.cpp:73:29: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   73 |                 int mid = l + r >> 1;
      |                           ~~^~~
jumps.cpp:87:33: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   87 |                     int mid = l + r >> 1;
      |                               ~~^~~
jumps.cpp: In function 'void init(int, std::vector<int>)':
jumps.cpp:126:68: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
  126 |             dp[j][i] = combine(dp[j - 1][i], dp[j - 1][i + (1 << j - 1)]);
      |                                                                  ~~^~~

• 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