Submission #796401

#	Time	Username	Problem	Language	Result	Execution time	Memory
796401		MadokaMagicaFan	Plus Minus (BOI17_plusminus)	C++14	Compilation error	0 ms	0 KiB

plusminus

#include "bits/stdc++.h"
using namespace std;
using ll = long long;

ll md = 1e9+7;

ll
pw(int x) {
	ll a = 1;
	ll c = 2;

	while (x) {
		if (x&1) a = (a * c) % md;
		c = (c * c) % md;
		x >>= 1;
	}

	return a;
}

int32_t main(int32_t argc, char *argv[])
{

	if (argc > 1) freopen(argv[1], "r", stdin);
	int n, m, k;
	char c;

	set<int> cx, cy;

	cin >> n >> m >> k;

	if (k == 0) {
		cout << (pw(m) + pw(n) - 2ll) << endl;
		return;
	}

	vector<array<int, 3>> pn(k);

	for (int i = 0; i < k; ++i) {
		cin >> c >> pn[i][1] >> pn[i][2];
		--pn[i][1], --pn[i][2];
		cy.insert(pn[i][1]);
		cx.insert(pn[i][2]);
		pn[i][0] = (c == '+') ? 0 : 1;
	}

	int hx, hy;
	hx = hy = 0;
	vector<array<int, 3>> sm(k);


	for (int i = 0; i < k; ++i) {
		sm[i][0] = pn[i][1];
		sm[i][1] = pn[i][2];
		sm[i][2] = pn[i][0];
	}

	sort(sm.begin(), sm.end());

	for (int i = 1; i < k; ++i) {
		if (sm[i][0] != sm[i-1][0]) continue;

		if (((sm[i][1] ^ sm[i][2]) ^ (sm[i-1][1] ^ sm[i-1][2])) & 1) {
			hx = 1; break;
		}
	}

	for (int i = 0; i < k; ++i) {
		sm[i][0] = pn[i][2];
		sm[i][1] = pn[i][1];
		sm[i][2] = pn[i][0];
	}

	sort(sm.begin(), sm.end());

	for (int i = 1; i < k; ++i) {
		if (sm[i][0] != sm[i-1][0]) continue;

		if (((sm[i][1] ^ sm[i][2]) ^ (sm[i-1][1] ^ sm[i-1][2])) & 1) {
			hy = 1; break;
		}
	}

	assert(n > 1);
	assert(m > 1);
	//TODO: test for not possible
	if (hx && hy) {
		cout << 0 << endl;
		return 0;
	}

	if (hx == 1) {
// PRINTX:
		cout << pw(m - cx.size()) << endl;
		return 0;
	}

	if (hy == 1) {
// PRINTY:
		cout << pw(n - cy.size()) << endl;
		return 0;
	}

	ll ans = (pw(m - cx.size()) + pw(n - cy.size()) - 1ll) % md;

	for (int i = 1; i < k; ++i) {
		if (((pn[i][0] ^ pn[i][1] ^ pn[i][2]) ^ (pn[0][0] ^ pn[0][1] ^ pn[0][2])) & 1) {
			ans = (ans + 1ll) % md;
			break;
		}
	}

	cout << ans << endl;
}

Compilation message (stderr)

plusminus.cpp: In function 'int32_t main(int32_t, char**)':
plusminus.cpp:34:3: error: return-statement with no value, in function returning 'int32_t' {aka 'int'} [-fpermissive]
   34 |   return;
      |   ^~~~~~
plusminus.cpp:24:23: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   24 |  if (argc > 1) freopen(argv[1], "r", stdin);
      |                ~~~~~~~^~~~~~~~~~~~~~~~~~~~~