Submission #1145813

#	Time	Username	Problem	Language	Result	Execution time	Memory
1145813		Shadow1	Cave (IOI13_cave)	C++20	100 / 100	633 ms	528 KiB

cave

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

void exploreCave(int N) {
    int n = N;
    int s[n], d[n];  // swtich combination and connected door.
    vector<bool> know(n);
    int res = -1;
    fill(s, s+n, 0);
    fill(d, d+n, 0);
    for(int k=0; k<n; ++k) {
        int l = 0, r = n-1;
        int q[n];
        for(int i=0; i<n; ++i)
            q[i] = (know[i] ? s[i] : 0);
        int init = tryCombination(q);
        bool one = 0;
        if(init == k)
            one = true;
        else
            one = false;
        int x = init;  // if init > k, correct switch lies somewhere
        while(l < r) {
            int m = (l + r) >> 1;
            for(int i=0; i<n; ++i) {
                if(know[i])
                    q[i] = s[i];
                else if(i >= l && i <= m) 
                    q[i] = (one ? 1 : 0);
                else 
                    q[i] = (one ? 0 : 1); 
            }

            x = tryCombination(q);
            if(x == -1) x = n;
            if(x > k)   // door changes state, correct switch on left
                r = m;
            else 
                l = m+1;
            
            res = x;
        }
        // if(k == 1) show(x);
        s[r] = (one ? 1 : 0);

        know[r] = true;
        d[r] = k;
        
    }
    answer(s, d);

}

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