Submission #1040004

#	Time	Username	Problem	Language	Result	Execution time	Memory
1040004		dpsaveslives	Rice Hub (IOI11_ricehub)	C++17	100 / 100	10 ms	3528 KiB

ricehub

#include <bits/stdc++.h>
#define ll long long
using namespace std;
const int MAXN = 1e5+10;
ll pref1[MAXN],pref2[MAXN],arr[MAXN];
int X[5] = {1,2,10,12,14};
int besthub(int R,int L,int X[],ll B){
    for(int i = 0;i<R;++i){
        arr[i+1] = X[i];
    }
    for(int i = 1;i<=R;++i){
        pref1[i] = pref1[i-1]+arr[i]; //-> pref[1] = distance from 1 to X[1]
        //cout << pref1[i] << "\n";
    }
    pref1[R+1] = L-pref1[R];
    /*for(int i = 1;i<=R+1;++i){
        pref2[i] = pref2[i-1]+pref1[i];
        cout << pref2[i] << "\n";
    }*/
    int lo = -1, hi = R;
    while(lo < hi){
        int mid = lo+(hi-lo+1)/2;
        bool good = false;
        if(mid % 2 == 0){
            int i = 1; //number of the first field, one-indexed and all
            while(i+mid-1 <= R){
                int m = (i+(mid/2));
                ll cur = pref1[i+mid-1]-pref1[m-1]-(pref1[m-1]-pref1[i-1]);
                //ll cur = pref1[i+mid]-pref1[m]-(pref1[m]-pref1[i]);
                //cout << i << " " << cur << " " << mid << "\n";
                if(cur <= B){
                    good = true;
                    break;
                }
                ++i;
            }
        }
        else{
            int i = 1; //number of the first field, one-indexed and all
            while(i+mid-1 <= R){
                int m = (i+(mid/2));
                ll cur = pref1[i+mid-1]-pref1[m]-(pref1[m-1]-pref1[i-1]);
                //ll cur = pref1[i+mid]-pref1[m+1]-(pref1[m]-pref1[i]);
                //cout << i << " " << cur << " " << mid << "\n";
                if(cur <= B){
                    good = true;
                    break;
                }
                ++i;
            }
        }
        if(good){
            lo = mid;
        }
        else{
            hi = mid-1;
        }
    }
    return lo;
}

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