Submission #843762

#	Time	Username	Problem	Language	Result	Execution time	Memory
843762		mickey080929	Memory 2 (JOI16_memory2)	C++14	100 / 100	1 ms	348 KiB

memory2

#include "Memory2_lib.h"
#include <bits/stdc++.h>

int Flip(int I, int J);
void Answer(int I, int J, int X);

using namespace std;

int ret[110];
int cnt[110];
int chk[110];
vector<int> ans[110];

void Solve(int T, int N) {
    mt19937 gen(1020301);
    uniform_int_distribution<int> dis(0, 1'000'000'000);
    int r = 2 * N;
    int ppv = -1, pre = -1;
    while (r>0) {
        if (r == 2) {
            int x = -1, y = -1;
            for (int i=0; i<2*N; i++) {
                if (!chk[i]) {
                    if (x == -1) x = i;
                    else y = i;
                }
            }
            ans[Flip(x, y)] = {x, y};
            break;
        }
        int idx = dis(gen) % (r - (ppv != -1));
        int pv;
        for (int i=0; i<2*N; i++) {
            if (!chk[i] && i != ppv) {
                if (idx == 0) {
                    pv = i;
                    break;
                }
                idx --;
            }
        }
        for (int i=0; i<N; i++) cnt[i] = 0;
        if (ppv != -1) {
            ret[ppv] = pre;
            cnt[pre] ++;
        }
        for (int i=0; i<2*N; i++) {
            if (pv == i || ppv == i || chk[i]) continue;
            ret[i] = Flip(pv, i);
            cnt[ret[i]] ++;
        }
        int cur = -1;
        for (int i=0; i<N; i++) {
            if (cnt[i] & 1) {
                cur = i;
                break;
            }
        }
        if (cur == pre) {
            ans[pre] = {ppv, pv};
            chk[ppv] = 1;
            chk[pv] = 1;
            r -= 2;
            ppv = -1;
            pre = -1;
            continue;
        }
        for (int i=0; i<2*N; i++) {
            if (pv == i || chk[i]) continue;
            if (ret[i] != cur) {
                ans[ret[i]].push_back(i);
                chk[i] = 1;
                r --;
            }
        }
        ppv = pv;
        pre = cur;
    }
    for (int i=0; i<N; i++) {
        //printf("%d %d\n", ans[i][0], ans[i][1]);
        Answer(ans[i][0], ans[i][1], i);
    }

	return;
}

Compilation message (stderr)

memory2.cpp: In function 'void Solve(int, int)':
memory2.cpp:49:26: warning: 'pv' may be used uninitialized in this function [-Wmaybe-uninitialized]
   49 |             ret[i] = Flip(pv, i);
      |                      ~~~~^~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 50 / 50
• Subtask 3: 40 / 40