Submission #1006725

#	Time	Username	Problem	Language	Result	Execution time	Memory
1006725		uma	Rice Hub (IOI11_ricehub)	C++14	68 / 100	8 ms	3420 KiB

ricehub

//#include "ricehub.h"
#include <iostream>
#include <vector>
#include <algorithm>


using namespace std;

typedef long long ll;

int besthub(int R, int L, int positions[], long long B){
    int n = R;

    int left = 0;
    
    int max_len = 0;
    vector<ll> prefix_vec(n,0);

    prefix_vec[0] = positions[0];

//calculating prefix sum
    for(int  i = 1; i < n; i++){
        prefix_vec[i] = prefix_vec[i-1] + positions[i];
    }

//sliding window concepts
    for(int right = 0; right < n; right++){
        int median = left + (right-left)/2;

        ll left_sum = (median > 0) ? prefix_vec[median - 1] - ((left > 0)?prefix_vec[left-1]:0):0;
        ll left_cost = (ll)(median-left)*positions[median] - left_sum;
        ll right_cost = (prefix_vec[right] - prefix_vec[median]) - (ll)(right - median)*positions[median];

        int currentCost = left_cost + right_cost;

        while(currentCost > B && median >= left){
            left++;

            median = left + (right-left)/2;

            left_sum = (median > 0) ? prefix_vec[median - 1] - ((left > 0)?prefix_vec[left-1]:0):0;
            left_cost = (ll)(median-left)*positions[median] - left_sum;
            right_cost = (prefix_vec[right] - prefix_vec[median]) - (ll)(right - median)*positions[median];
            
            currentCost = left_cost + right_cost;
        } 

        max_len = max(max_len,right-left+1);
    }

    return max_len;
}

• Subtask 1: 17 / 17
• Subtask 2: 25 / 25
• Subtask 3: 26 / 26
• Subtask 4: 0 / 32