Submission #1080449

#	Time	Username	Problem	Language	Result	Execution time	Memory
1080449		andrei_iorgulescu	Plus Minus (BOI17_plusminus)	C++14	100 / 100	144 ms	21332 KiB

plusminus

#include <bits/stdc++.h>

using namespace std;

int modulo = 1e9 + 7;

int n,m,k;

int lgpow(int x, int y)
{
    int z = 1;
    while (y != 0)
    {
        if (y % 2 == 1)
            z = 1ll * z * x % modulo;
        x = 1ll * x * x % modulo;
        y /= 2;
    }
    return z;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    cin >> n >> m >> k;
    bool nah1 = false, nah2 = false;
    set<int> ff1, ff2;
    map<int,int> lin, col;
    bool could_be_chessboard_1 = true, could_be_chessboard_2 = true;
    for (int i = 1; i <= k; i++)
    {
        char spin;
        int x,y;
        cin >> spin >> x >> y;
        ff1.insert(x);
        ff2.insert(y);
        if (spin == '+' and (x + y) % 2 == 0)
            could_be_chessboard_1 = false;
        if (spin == '+' and (x + y) % 2 == 1)
            could_be_chessboard_2 = false;
        if (spin == '-' and (x + y) % 2 == 0)
            could_be_chessboard_2 = false;
        if (spin == '-' and (x + y) % 2 == 1)
            could_be_chessboard_1 = false;
        if (spin == '+')
        {
            if (lin[x] != 0)
            {
                if (lin[x] != 1 + y % 2)
                {
                    nah1 = true;
                }
            }
            else
                lin[x] = 1 + y % 2;
        }
        else
        {
            if (lin[x] != 0)
            {
                if (lin[x] != 1 + (y - 1) % 2)
                {
                    nah1 = true;
                }
            }
            else
                lin[x] = 1 + (y - 1) % 2;
        }

        if (spin == '+')
        {
            if (col[y] != 0)
            {
                if (col[y] != 1 + x % 2)
                {
                    nah2 = true;
                }
            }
            else
                col[y] = 1 + x % 2;
        }
        else
        {
            if (col[y] != 0)
            {
                if (col[y] != 1 + (x - 1) % 2)
                {
                    nah2 = true;
                }
            }
            else
                col[y] = 1 + (x - 1) % 2;
        }
    }
    int ans = 0;
    if (!nah1)
        ans += lgpow(2, n - (int)ff1.size());
    if (!nah2)
        ans += lgpow(2, m - (int)ff2.size());
    if (could_be_chessboard_1)
        ans--;
    if (could_be_chessboard_2)
        ans--;
    cout << ans % modulo;
    return 0;
}

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