Submission #247714

#	Time	Username	Problem	Language	Result	Execution time	Memory
247714		Nightlight	Cave (IOI13_cave)	C++14	100 / 100	790 ms	804 KiB

cave

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

int N;
bool found[5005];
int S[5005], D[5005];

void solve(int pos) {
    int C[N];
    int init;
    vector<int> pen;
    for(int i = 0; i < N; i++) {
        if(found[i] == 0) {
            pen.push_back(i);
        }
        C[i] = 0;
    }
    for(int i = 0; i < pos; i++) C[D[i]] = S[i];
    int now = tryCombination(C);
    if(now != pos) init = 0, S[pos] = 0;
    else init = 1, S[pos] = 1;
    int l = 0, r = pen.size() - 1, res;
    while(l <= r) {
        int mid = (l + r) >> 1;
        for(int i = 0; i <= mid; i++) {
            C[pen[i]] = init;
        }
        for(int i = mid + 1; i < pen.size(); i++) {
            C[pen[i]] = !init;
        }
        if(tryCombination(C) != pos) {
            r = mid - 1;
            res = mid;
        }else l = mid + 1;
    }
    found[pen[res]] = 1;
    D[pos] = pen[res];
}

void exploreCave(int n) {
    N = n;
    for(int i = 0; i < N; i++) {
        solve(i);
//        cout << D[i] << "\n";
    }
    int s[n], d[n];
    for(int i = 0; i < n; i++) {
        d[D[i]] = i;
        s[D[i]] = S[i];
    }
    answer(s, d);
}

Compilation message (stderr)

cave.cpp: In function 'void solve(int)':
cave.cpp:29:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i = mid + 1; i < pen.size(); i++) {
                              ~~^~~~~~~~~~~~
cave.cpp:37:18: warning: 'res' may be used uninitialized in this function [-Wmaybe-uninitialized]
     found[pen[res]] = 1;
                  ^

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