Submission #1280296

#	Time	Username	Problem	Language	Result	Execution time	Memory
1280296		quangminh412	Plus Minus (BOI17_plusminus)	C++17	12 / 100	2 ms	580 KiB

plusminus

/*
  Ben Watson

  Quang Minh MasterDDDDD
*/

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

#define ll long long

const string name = "test";

void solve();
signed main()
{
    if (fopen((name + ".inp").c_str(), "r"))
    {
        freopen((name + ".inp").c_str(), "r", stdin);
        freopen((name + ".out").c_str(), "w", stdout);
    }
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    solve();

    return 0;
}

// main program
const int maxk = 1e5 + 5;
const int mod = 1e9 + 7;

int mul(int a, int b) { return 1ll * a * b % mod; }
int power(int a, int b)
{
    int res = 1;
    for (; b != 0; b /= 2, a = mul(a, a))
        if (b & 1)
            res = mul(res, a);
    return res;
}

bool cmpX(const array<int, 3>& a, const array<int, 3>& b)
{
    if (a[1] != b[1]) return a[1] < b[1];
    return a[2] < b[2];
}

bool cmpY(const array<int, 3>& a, const array<int, 3>& b)
{
    if (a[2] != b[2]) return a[2] < b[2];
    return a[1] < b[1];
}

vector<array<int, 3>> elecs;
int n, m, k;

int count_rows()
{
    sort(elecs.begin(), elecs.end(), cmpX);
    int res = 0, prev = 0;
    for (int l = 0, r = -1; l < k; l = r + 1)
    {
        r++;
        while (r + 1 < k && elecs[r + 1][1] == elecs[r][1])
            r++;
        for (int i = l; i <= r; i++)
        {
            int val1 = (elecs[i][2] ^ elecs[l][2]) & 1, val2 = (elecs[i][0] ^ elecs[l][0]);
            if (val1 != val2)
                return 0;
        }
        res += elecs[l][1] - prev - 1;
        prev = elecs[l][1];
    }
    res += n - prev;
    return power(2, res);
}

int count_cols()
{
    sort(elecs.begin(), elecs.end(), cmpY);
    int res = 0, prev = 0;
    for (int l = 0, r = -1; l < k; l = r + 1)
    {
        r++;
        while (r + 1 < k && elecs[r + 1][2] == elecs[r][2])
            r++;
        for (int i = l; i <= r; i++)
        {
            int val1 = (elecs[i][1] ^ elecs[l][1]) & 1, val2 = (elecs[i][0] ^ elecs[l][0]);
            if (val1 != val2)
                return 0;
        }
        res += elecs[l][2] - prev - 1;
        prev = elecs[l][2];
    }
    res += m - prev;
    return power(2, res);
}

int count_both()
{
    for (int i = 0; i < k; i++)
    {
        int val1 = (elecs[i][1] ^ elecs[i][2] ^ elecs[0][1] ^ elecs[0][2]) & 1;
        int val2 = (elecs[i][0] ^ elecs[0][0]);
        if (val1 != val2)
            return 0;
    }
    return 1;
}

void solve()
{
    cin >> n >> m >> k;
    for (int i = 0; i < k; i++)
    {
        char t; cin >> t;
        int sign = (t == '+' ? 1 : 0);
        int x, y; cin >> x >> y;

        elecs.push_back({sign, x, y});
    }

    int val1 = count_rows();
    int val2 = count_cols();
    int exclude = count_both();
    int res = (val1 + val2 - exclude + mod) % mod;
    if (k == 0)
        res = (res - 1 + mod) % mod;

    cout << res << '\n';
}

Compilation message (stderr)

plusminus.cpp: In function 'int main()':
plusminus.cpp:19:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   19 |         freopen((name + ".inp").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
plusminus.cpp:20:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   20 |         freopen((name + ".out").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 0 / 42
• Subtask 3: 0 / 46