Fishers

input/code.cpp: In function 'void Test()':
input/code.cpp:50:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   50 |     freopen("temp\\in.txt", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
const int N=100005;


int buc_true[2*N], buc_false[2*N];
int group[2*N], cur_group;

int n;
inline int Inc(int x)
{
    if(x == 2*n) 
        return 1;
    return x + 1;
}
inline int Dec(int x)
{
    if(x == 1)
        return 2 * n;
    return x - 1;
}

void ColorInc(int u, int v, int c)
{
    // from u -> v, inc
    int x = u, t = group[x];
    x = Inc(x);
    while(group[x] == t && x != v)
    {
        group[x] = c;
        x = Inc(x);
    }
}
void ColorDec(int u, int v, int c)
{
    // from u -> v, inc
    int x = u, t = group[x];
    x = Dec(x);
    while(group[x] == t && x != v)
    {
        group[x] = c;
        x = Dec(x);
    }
}


void Test()
{
    freopen("temp\\in.txt", "r", stdin);
}
int main()
{
    // Test();
    cin >> n;
    for(int i=1; i<=2*n; i++)
    {
        int x;
        cin >> x;
        if(x < 0) {
            x = -x;
            buc_false[x] = i;
        } else {
            buc_true[x] = i;
        }
    }

    bool flag = false;
    for(int i=1; i<=n; i++)
    {
        int u = buc_true[i], v = buc_false[i];
        if(group[u] != group[v])
        {
            flag = true;
            break;
        }
        // re-group them
        int uc = ++cur_group;
        int vc = ++cur_group;

        ColorInc(u, v, uc);
        ColorDec(v, u, uc);
        ColorInc(v, u, vc);
        ColorDec(u, v, vc);
// for(int i=1; i<=2*n; i++)
//     cout << group[i] <<" ";
// putchar('\n');
    }
    if(flag)
        cout << "Yes";
    else
        cout << "No";



    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

Verdict: WRONG ANSWER

Test 22

Verdict: WRONG ANSWER

Test 23

Verdict: WRONG ANSWER

Test 24

Verdict: WRONG ANSWER

Test 25

Verdict: ACCEPTED

Test 26

Verdict: WRONG ANSWER

Test 27

Verdict: ACCEPTED

Test 28

Verdict: ACCEPTED

Test 29

Verdict: ACCEPTED

Test 30

Verdict: WRONG ANSWER

Test 31

Verdict: WRONG ANSWER

Test 32

Verdict: WRONG ANSWER

Test 33

Verdict: WRONG ANSWER

Test 34

Verdict: WRONG ANSWER

Test 35

Verdict: ACCEPTED

Test 36

Verdict: WRONG ANSWER

Test 37

Verdict: ACCEPTED

Test 38

Verdict: WRONG ANSWER

Test 39

Verdict: ACCEPTED

Test 40

Verdict: WRONG ANSWER

Test 41

Verdict: WRONG ANSWER

Test 42

Verdict: WRONG ANSWER

Test 43

Verdict: WRONG ANSWER

Test 44

Verdict: WRONG ANSWER

Test 45

Verdict: ACCEPTED

Test 46

Verdict: WRONG ANSWER

Test 47

Verdict: ACCEPTED

Test 48

Verdict: WRONG ANSWER

Test 49

Verdict: ACCEPTED

Test 50

Verdict: WRONG ANSWER

Test 51

Verdict: WRONG ANSWER

Test 52

Verdict: WRONG ANSWER

Test 53

Verdict: WRONG ANSWER

Test 54

Verdict: WRONG ANSWER

Test 55

Verdict: ACCEPTED

Test 56

Verdict: WRONG ANSWER

Test 57

Verdict: ACCEPTED

Test 58

Verdict: WRONG ANSWER

Test 59

Verdict: ACCEPTED

Test 60

Verdict: WRONG ANSWER

Test 61

Verdict: WRONG ANSWER

Test 62

Verdict: WRONG ANSWER

Test 63

Verdict: WRONG ANSWER

Test 64

Verdict: WRONG ANSWER

Test 65

Verdict: ACCEPTED