Submission #542741

#	Time	Username	Problem	Language	Result	Execution time	Memory
542741		collodel	Cave (IOI13_cave)	C++17	0 / 100	2080 ms	340 KiB

cave

#include "cave.h"
#include <vector>

using namespace std;

void flip(int arr[], int start, int end) {
    while(start != end) {
        arr[start] ^= 1; 
    }
}

void unset(int arr[], int start, int end) {
    while(start != end) {
        arr[start] = 0; 
    }
}

void fix(int ans[], int ask[], int corr[], int start, int end, int n) {
    for(int i = 0; i < n; ++i) {
        if(ans[i] >= start && ans[i] < end)
            ask[ans[i]] = corr[i];
    }
}

void exploreCave(int N) {
    int ans[N];
    int ask[N];
    int corr[N];

    for(int i = 0; i < N; ++i) {
        ans[i] = -1, ask[i] = 0, corr[i] = 0;
    }

    for(int i = 0; i < N; ++i) {
        // trova se serve accendere o spegnere
        unset(ask, 0, N);
        fix(ans, ask, corr, 0, N, N);

        bool state = (tryCombination(ask) <= i);
        if(state)
            flip(ask, 0, N), fix(ans, ask, corr, 0, N, N);

        // bs
        int l = 0, r = N;
        while(l != r) {
            int m = (l+r)/2;
            flip(ask, l, m);
            fix(ans, ask, corr, l, m, N);
            if(tryCombination(ask) > i) {
                // porta aperta, segui [l, m)
                r = m;
            } else {
                // porta chiusa, segui [m, r)
                l = m;
            }
            flip(ask, l, m);
            fix(ans, ask, corr, l, m, N);
        }

        ans[l] = i;
        corr[l] = state;
    }

    answer(corr, ans);
}

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