Submission #1307934

#TimeUsernameProblemLanguageResultExecution timeMemory
1307934faricaPlus Minus (BOI17_plusminus)C++20
Compilation error
0 ms0 KiB
#include<bits/stdc++.h>
using namespace std;
using vi = vector<int>;
using pi = pair<int,int>;
typedef long long ll;
#define debug(x) cout << #x << " = " << x << "\n";
#define vdebug(a) cout << #a << " = "; for(auto x: a) cout << x << " "; cout << "\n";

const int MOD = 1e9 + 7;
const int INF = 1e9;

template<ll mod>
struct modnum {
	static constexpr bool is_big_mod = mod > numeric_limits<int>::max();

	using S = conditional_t<is_big_mod, ll, int>;
	using L = conditional_t<is_big_mod, __int128, ll>;

	S x;

	modnum() : x(0) {}
	modnum(ll _x) {
		_x %= static_cast<ll>(mod);
		if (_x < 0) { _x += mod; }
		x = _x;
	}

	modnum pow(ll n) const {
		modnum res = 1;
		modnum cur = *this;
		while (n > 0) {
			if (n & 1) res *= cur;
			cur *= cur;
						n /= 2;
		}
		return res;
	}
	modnum inv() const { return (*this).pow(mod-2); }

	modnum& operator+=(const modnum& a){
		x += a.x;
		if (x >= mod) x -= mod;
		return *this;
	}
	modnum& operator-=(const modnum& a){
		if (x < a.x) x += mod;
		x -= a.x;
		return *this;
	}
	modnum& operator*=(const modnum& a){
		x = static_cast<L>(x) * a.x % mod;
		return *this;
	}
	modnum& operator/=(const modnum& a){ return *this *= a.inv(); }

	friend modnum operator+(const modnum& a, const modnum& b){ return modnum(a) += b; }
	friend modnum operator-(const modnum& a, const modnum& b){ return modnum(a) -= b; }
	friend modnum operator*(const modnum& a, const modnum& b){ return modnum(a) *= b; }
	friend modnum operator/(const modnum& a, const modnum& b){ return modnum(a) /= b; }

	friend bool operator==(const modnum& a, const modnum& b){ return a.x == b.x; }
	friend bool operator!=(const modnum& a, const modnum& b){ return a.x != b.x; }
	friend bool operator<(const modnum& a, const modnum& b){ return a.x < b.x; }

	friend ostream& operator<<(ostream& os, const modnum& a){ os << a.x; return os; }
	friend istream& operator>>(istream& is, modnum& a) { ll x; is >> x; a = modnum(x); return is; }
};

using mint = modnum<MOD>;

template <class T> class SumSegmentTree {
  private:
	const T DEFAULT = 0;

	vector<T> segtree;
	int len;

  public:
	SumSegmentTree(int len) : len(len), segtree(len * 2, DEFAULT) {}

	void set(int ind, T val) {
		ind += len;
		segtree[ind] = val;
		for (; ind > 1; ind /= 2) {
			segtree[ind / 2] = segtree[ind] + segtree[ind ^ 1];
		}
	}

	T range_sum(int start, int end) {
		T sum = DEFAULT;
		for (start += len, end += len; start < end; start /= 2, end /= 2) {
			if (start % 2 == 1) { sum += segtree[start++]; }
			if (end % 2 == 1) { sum += segtree[--end]; }
		}
		return sum;
	}
};

struct BIT {
  vector<ll>b;
  int n;

  void init(int _n) {
	n = _n ;
	b.assign(n+1, 0);
  }
  inline int lowbit(int x) { return x & (-x); }
  void update(int x, ll v) {
	  ++x;
	for(int i = x ; i <= n ; i += lowbit(i)) b[i] += v;
  }
  ll query(int x) {
	ll ans = 0;
	++x;
	for(int i = x ; i > 0 ; i -= lowbit(i)) ans += b[i];
	return ans;
  }
} bit;

int gcd(int a, int b, int& x, int& y) { // x*a + y*b = a1
    x = 1, y = 0;
    int x1 = 0, y1 = 1, a1 = a, b1 = b;
    while (b1) {
        int q = a1 / b1;
        tie(x, x1) = make_tuple(x1, x - q * x1);
        tie(y, y1) = make_tuple(y1, y - q * y1);
        tie(a1, b1) = make_tuple(b1, a1 - q * b1);
    }
    return a1;
}

int inv_ecd(int a, int m) {
	int x, y;
	int g = gcd(a, m, x, y);
	if(g != 1) return -1;
	x = (x + m) % m;
	return x;
}

ll exp(ll x, ll n) {
	ll res = 1;
	while (n > 0) {
		if (n % 2 == 1) { res = res * x % MOD; }
		x = x * x % MOD;
		n /= 2;
	}
	return res;
}

char inv(char c) { return (c == '-' ? '+' : '-'); } 

void solve() {
	int n, m, k;
	cin >> n >> m >> k;
	map<int,char>row, col;
	bool rowPoss = 1, colPoss = 1;
	for(int i=0; i<k; ++i) {
		int x, y;
		char c;
		cin >> c >> x >> y;
		if(row[x]) {
			char exp = row[x];
			if(y%2==0) exp = inv(exp);
			if(exp != c) rowPoss = 0;
		} else {
			char exp = col[y];
			if(x%2==0) exp = inv(exp);
			if(exp != c) colPoss = 0;
		}
		row[x] = (y%2==0 ? inv(c) : c);
		col[y] = (x%2==0 ? inv(c) : c);
	}
	if(!rowPoss && !colPoss) {
		cout << 0 << endl;
		return;
	}
	int ans = 0;
	if(rowPoss) {
		int left = n - (int)row.size();
		ans = (ans + exp(2, left)) % MOD;
	}  
	if(colPoss) {
		int left = m - (int)col.size();
		ans = (ans + exp(2, left)) % MOD;
	}
	int rem = 1, prev = -1;
	char prv = '';
	for(auto it = row.begin(); it != row.end(); ++it) {
		if(it->first == prev+1 && prv == it->second) rem = 0;
		prev = it->first;
		prv = it->second;
	}
	prev = -1;
	for(auto it = col.begin(); it != col.end(); ++it) {
		if(it->first == prev+1 && prv == it->second) rem = 0;
		prev = it->first;
		prv = it->second;
	}
	ans -= rem;
	cout << ans << endl;
} 

int main(){
	ios::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);

	int tc=1;
	while(tc--) {
		solve();
	}

}
 

Compilation message (stderr)

plusminus.cpp:187:20: error: empty character constant
  187 |         char prv = '';
      |                    ^~