Submission #587472

#	Time	Username	Problem	Language	Result	Execution time	Memory
587472		usuyus	Robots (IOI13_robots)	C++14	100 / 100	660 ms	25120 KiB

robots

#include "robots.h"

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

int putaway(int A, int B, int T, int X[], int Y[], int W[], int S[]) {
    sort(X, X+A); sort(Y, Y+B);

    vector<vector<int>> pts(B+1);
    vector<int> init_up(A+1), init_right(B+1);
    
    for (int i=0; i<T; i++){
        int x = upper_bound(X, X+A, W[i]) - X;
        int y = upper_bound(Y, Y+B, S[i]) - Y;

        if (x == A && y == B) return -1;
        else if (x == A) ++init_right[y];
        else if (y == B) ++init_up[x];
        else pts[y].push_back(x);
    }

    for (auto &v : pts) sort(v.begin(), v.end());

    auto try_answer = [&] (int k) {
        auto up = init_up, right = init_right;

        priority_queue<int> pq;
        
        for (int i=0; i<B; i++) {
            for (int j : pts[i]) pq.push(j);

            while (!pq.empty() && right[i] < k) {
                int j = pq.top(); pq.pop();
                ++right[i];
            }

            if (right[i] > k) {
                right[i+1] += right[i] - k;
                right[i] = k;
            }
        }

        while (!pq.empty()) {
            int j = pq.top(); pq.pop();
            ++up[j];
        }

        for (int j=0; j<A; j++) {
            if (up[j] > k) {
                up[j+1] += up[j] - k;
                up[j] = k;
            }
        }

        // cout << k << " -> " << (up[A] == 0 && right[B] == 0) << endl;

        return up[A] == 0 && right[B] == 0;
    };

    int l = 0, r = T;
    while ((r-l) > 1) {
        int m = (l+r) / 2;
        if (try_answer(m)) r = m;
        else l = m;
    }

    return r;
}

Compilation message (stderr)

robots.cpp: In lambda function:
robots.cpp:33:21: warning: unused variable 'j' [-Wunused-variable]
   33 |                 int j = pq.top(); pq.pop();
      |                     ^

• Subtask 1: 14 / 14
• Subtask 2: 14 / 14
• Subtask 3: 25 / 25
• Subtask 4: 37 / 37
• Subtask 5: 10 / 10