Submission #611953

#	Time	Username	Problem	Language	Result	Execution time	Memory
611953		Jomnoi	Meetings (IOI18_meetings)	C++17	19 / 100	1416 ms	20720 KiB

meetings

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

const int MAX_N = 75e4 + 5;
const long long INF = 1e18 + 7;

int N, Q;
long long H[MAX_N];
pair <int, int> table[MAX_N][20];
int table2[MAX_N][20];
vector <int> graph[MAX_N];

pair <int, int> getMax(int l, int r) {
    int j = log2(r - l + 1);
    return max(table[l][j], table[r - (1<<j) + 1][j]);
}

int getMin(int l, int r) {
    int j = log2(r - l + 1);
    return min(table2[l][j], table2[r - (1<<j) + 1][j]);
}

int build_tree(int l, int r) {
    if(l > r) {
        return -1;
    }

    int u = getMax(l, r).second;
    int L = build_tree(l, u - 1);
    int R = build_tree(u + 1, r);
    if(L != -1) {
        graph[u].push_back(L);
    }
    if(R != -1) {
        graph[u].push_back(R);
    }
    return u;
}

long long dfs(int u, int l, int r, long long total = 0) {
    long long now = total + H[u] * (r - l + 1);
    for(auto v : graph[u]) {
        if(v < u) {
            now = min(now, dfs(v, l, u - 1, total + H[u] * (r - u + 1)));
        }
        else {
            now = min(now, dfs(v, u + 1, r, total + H[u] * (u - l + 1)));
        }
    }
    return now;
}

vector <long long> minimum_costs(vector <int> h, vector <int> L, vector <int> R) {
    N = h.size(), Q = L.size();
    vector <long long> C;
    for(int i = 1; i <= N; i++) {
        H[i] = h[i - 1];
    }
    for(int i = 0; i < Q; i++) {
        L[i]++, R[i]++;
    }

    if(N <= 5000 and Q <= 5000) {
        for(int i = 1; i <= N; i++) {
            table[i][0] = make_pair(H[i], i);
        }
        for(int j = 1; j < 20; j++) {
            for(int i = 1; i + (1<<j) - 1 <= N; i++) {
                table[i][j] = max(table[i][j - 1], table[i + (1<<(j - 1))][j - 1]);
            }
        }

        for(int i = 0; i < Q; i++) {
            for(int i = 1; i <= N; i++) {
                graph[i].clear();
            }
            C.push_back(dfs(build_tree(L[i], R[i]), L[i], R[i]));
        }
    }
    else {
        for(int i = 1; i <= N; i++) {
            table2[i][0] = H[i];
        }
        for(int j = 1; j < 20; j++) {
            for(int i = 1; i + (1<<j) - 1 <= N; i++) {
                table2[i][j] = min(table2[i][j - 1], table2[i + (1<<(j - 1))][j - 1]);
            }
        }

        for(int i = 0; i < Q; i++) {
            int l = L[i], r = R[i], pos1 = N + 2, pos2 = N + 1;
            while(l <= r) {
                int mid = (l + r) / 2;

                if(getMin(L[i], mid) == 1) {
                    r = mid - 1;
                    pos1 = mid;
                }
                else {
                    l = mid + 1;
                }
            }

            l = pos1, r = R[i];
            while(l <= r) {
                int mid = (l + r) / 2;

                if(getMin(pos1, mid) == 1) {
                    l = mid + 1;
                    pos2 = mid;
                }
                else {
                    r = mid - 1;
                }
            }

            C.push_back((pos2 - pos1 + 1) + 2 * ((R[i] - L[i] + 1) - (pos2 - pos1 + 1)));
        }
    }
    return C;
}

• Subtask 1: 4 / 4
• Subtask 2: 15 / 15
• Subtask 3: 0 / 17
• Subtask 4: 0 / 24
• Subtask 5: 0 / 40