Submission #971350

#	Time	Username	Problem	Language	Result	Execution time	Memory
971350		Acanikolic	Cave (IOI13_cave)	C++14	51 / 100	168 ms	604 KiB

cave

#include <bits/stdc++.h>

#include "cave.h"

using namespace std;

void exploreCave(int N) {
    int S[N],D[N];
    for(int i = 0; i < N; i++) {
        S[i] = 0;
        D[i] = -1;
    }
    for(int Q = 0; Q < N; Q++) {
        int X = tryCombination(S);
        int l = 0, r = N - 1,ans = -1;
        while(l <= r) {
            int mid = (l + r) / 2;
            for(int i = l; i <= mid; i++) if(D[i] == -1) S[i] ^= 1;
            int Y = tryCombination(S);
            for(int i = l; i <= mid; i++) if(D[i] == -1) S[i] ^= 1;
            if(X != Y) {
                ans = mid;
                r = mid - 1;
            }else {
                l = mid + 1;
            }
        }
        assert(ans != -1);
        D[ans] = X;
        S[ans] ^= 1;
        if(X == -1) {
            D[ans] = tryCombination(S);
            S[ans] ^= 1;
        }
        else if(tryCombination(S) < X && tryCombination(S) != -1) {
            D[ans] = tryCombination(S);
            S[ans] ^= 1;
        }
    }
    answer(S,D);
}

• Subtask 1: 0 / 12
• Subtask 2: 0 / 13
• Subtask 3: 21 / 21
• Subtask 4: 30 / 30
• Subtask 5: 0 / 24