Submission #440723

#	Time	Username	Problem	Language	Result	Execution time	Memory
440723		aryan12	Cave (IOI13_cave)	C++17	100 / 100	368 ms	452 KiB

cave

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

void exploreCave(int N) {
    bool finalized[N];
    int CurState[N], connectDoor[N];
    for(int i = 0; i < N; i++) {
        finalized[i] = false;
        CurState[i] = 0;
        connectDoor[i] = -1;
    }
    for(int i = 0; i < N; i++) {
        int StateHere[N];
        for(int j = 0; j < N; j++) {
            StateHere[j] = CurState[j];
        }
        int maxDoor = tryCombination(StateHere);
        /*
        mandatory for ith door to be closed
        */
        if(maxDoor != i) {
            for(int j = 0; j < N; j++) {
                if(!finalized[j]) {
                    StateHere[j] = 1 - StateHere[j];
                }
            }
        }
        int l = 0, r = N - 1;
        int mid, ans = N;
        while(l <= r) {
            mid = (l + r) >> 1;
            for(int j = l; j <= mid; j++) {
                if(!finalized[j]) {
                    StateHere[j] = 1 - StateHere[j];
                }
            }
            int temp = tryCombination(StateHere);
            if(temp != i) { //this brought change, so the door must be within l and mid
                ans = mid;
                r = mid - 1;
                for(int j = l; j <= mid; j++) {
                    if(!finalized[j]) {
                        StateHere[j] = 1 - StateHere[j];
                    }
                }
            }
            else { //door between mid + 1 and r
                l = mid + 1;
            }
        }
        finalized[ans] = true;
        CurState[ans] = 1 - StateHere[ans];
        connectDoor[ans] = i;
    }
    return answer(CurState, connectDoor);
}

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