Submission #107686

#	Time	Username	Problem	Language	Result	Execution time	Memory
107686		FiloSanza	Cave (IOI13_cave)	C++14	100 / 100	1367 ms	640 KiB

cave

#include "cave.h"
#include <bits/stdc++.h>

using namespace std;

void setV(vector<int>& a, const vector<int>& b, int x, int y, int val){
    for(int i=x; i<=y; i++) if(b[i] == -1)
        a[i] = val;
}

void exploreCave(int N) {
    vector<int> pos(N, -1);
    vector<int> ans(N, -1);
    vector<int> idx(N, -1);

    for(int i=0; i<N; i++){
        //cerr << i << "\n";
        int lo = 0, hi = N-1, val = 0, x;
        setV(pos, ans, lo, hi, val);
        
        int dist = tryCombination(pos.data());
        if(dist == - 1) dist = N;
        if(dist < i+1) val = 1, setV(pos, ans, lo, hi, val);

        while(lo < hi){
            int mid = (lo+hi)/2;
            setV(pos, ans, lo, mid, val^1);
            int dist = tryCombination(pos.data());
            if(dist == -1) dist = N;

            //cerr << lo << " " << hi << " " << mid << " " << val <<" -> " << dist<< "\n";
            if(dist >= i+1){
                lo = mid+1;
                while(ans[lo] != -1) lo++;
            }
            else{
                hi = mid;
                while(ans[hi] != -1) hi--;
            }
            
            setV(pos, ans, 0, N-1, val);
        }
        //cerr << "\t" << lo << "\n";
        pos[lo] = val;
        idx[lo] = i;
        ans[lo] = val;
    }

    answer(ans.data(), idx.data());
}

Compilation message (stderr)

cave.cpp: In function 'void exploreCave(int)':
cave.cpp:18:40: warning: unused variable 'x' [-Wunused-variable]
         int lo = 0, hi = N-1, val = 0, x;
                                        ^

• Subtask 1: 12 / 12
• Subtask 2: 13 / 13
• Subtask 3: 21 / 21
• Subtask 4: 30 / 30
• Subtask 5: 24 / 24