Submission #92899

#	Time	Username	Problem	Language	Result	Execution time	Memory
92899		stefdasca	Robots (IOI13_robots)	C++14	14 / 100	327 ms	11740 KiB

robots

/*
    As it is usual for such problems, we can binary search the answer

    At each step, we will try to assign toys to the weak robots, then to the small robots. Since we will use a priority queue, checking will be done
at each step in O(T log T)

    Therefore, the total complexity will be O(T log^2 T)

*/

#include"robots.h"
#include<bits/stdc++.h>
using namespace std;
bool scos[1000002];
int putaway(int A, int B, int T, int X[], int Y[], int W[], int S[])
{
    int j = 0;
    sort(X, X+A);
    sort(Y, Y+B);
    vector<pair<int, int> >v;
    for(int i = 0; i < T; ++i)
        v.push_back({W[i], S[i]});
    sort(v.begin(), v.end());
    int b = 0;
    int e = 10000002;
    bool findd = 0;
    int ans = 0;
    while(b <= e)
    {
        int mid = (b + e) / 2;
        for(int i = 0; i < T; ++i)
            scos[i] = 0;
        deque<int>D;
        int ptra = 0;
        for(int i = 0; i < A; ++i)
        {
            while(ptra < T && X[i] > v[ptra].first)
                D.push_back(ptra), ++ptra;
            for(int j = 1; j <= mid && !D.empty(); ++j)
                scos[D.back()] = 1, D.pop_back();
        }
        vector<int>v2;
        for(int i = 0; i < T; ++i)
            if(!scos[i])
                v2.push_back(v[i].second);
        sort(v2.begin(), v2.end());
        for(int i = 0; i < v2.size(); ++i)
            scos[i] = 0;
        D.clear();
        ptra = v2.size() - 1;
        for(int i = B-1; i >= 0; --i)
        {
            while(ptra >= 0 && v2[ptra] < Y[i])
                D.push_front(ptra), --ptra;
            for(int j = 1; j <= mid && !D.empty(); ++j)
                scos[D.back()] = 1, D.pop_back();
        }
        bool gg = 1;
        for(int i = 0; i < v2.size(); ++i)
            if(!scos[i])
                gg = 0;
        if(gg)
            findd = 1, ans = mid, e = mid - 1;
        else
            b = mid + 1;
    }
    if(!findd)
        return -1;
    return ans;
}

Compilation message (stderr)

robots.cpp: In function 'int putaway(int, int, int, int*, int*, int*, int*)':
robots.cpp:47:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i = 0; i < v2.size(); ++i)
                        ~~^~~~~~~~~~~
robots.cpp:59:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i = 0; i < v2.size(); ++i)
                        ~~^~~~~~~~~~~
robots.cpp:17:9: warning: unused variable 'j' [-Wunused-variable]
     int j = 0;
         ^

• Subtask 1: 0 / 14
• Subtask 2: 14 / 14
• Subtask 3: 0 / 25
• Subtask 4: 0 / 37
• Subtask 5: 0 / 10