Submission #499742

#	Time	Username	Problem	Language	Result	Execution time	Memory
499742		pavement	Mobitel (COCI19_mobitel)	C++17	26 / 130	52 ms	18112 KiB

mobitel

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#ifdef _WIN32
#define getchar_unlocked _getchar_nolock
#endif
#define int long long
#define mp make_pair
#define mt make_tuple
#define pb push_back
#define ppb pop_back
#define eb emplace_back
#define g0(a) get<0>(a)
#define g1(a) get<1>(a)
#define g2(a) get<2>(a)
#define g3(a) get<3>(a)
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
typedef double db;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> ii;
typedef tuple<int, int, int> iii;
typedef tuple<int, int, int, int> iiii;
typedef tree<ii, null_type, less<ii>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;

const int MOD = 1e9 + 7;
int R, S, N, ans, sub, fac[605], invfac[605], A[305][305], dp[2][305][2005];
vector<int> vec;

int exp_mod(int a, int b) {
	int r = 1;
	while (b) {
		if (b & 1ll) r = r * a % MOD;
		a = a * a % MOD;
		b >>= 1ll;
	}
	return r;
}

main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin >> R >> S >> N;
	fac[0] = invfac[0] = 1;
	for (int i = 1; i <= 600; i++) {
		fac[i] = fac[i - 1] * i % MOD;
		invfac[i] = exp_mod(fac[i], MOD - 2);
	}
	sub = fac[R + S - 2] * invfac[R - 1] % MOD * invfac[S - 1] % MOD;
	N--;
	for (int i = 1; i <= R; i++)
		for (int j = 1; j <= S; j++) cin >> A[i][j];
	for (int i = 1; i <= N; i++) vec.pb(N / i);
	sort(vec.begin(), vec.end());
	vec.erase(unique(vec.begin(), vec.end()), vec.end());
	for (int i = 1; i <= R; i++)
		for (int j = 1; j <= S; j++) {
			if (i == 1 && j == 1) dp[i & 1][j][N / A[1][1]]++;
			else {
				for (int k : vec) dp[i & 1][j][k] = 0;
				for (int k : vec) {
					if (i > 1) {
						dp[i & 1][j][k / A[i][j]] += dp[i & 1 ^ 1][j][k];
						dp[i & 1][j][k / A[i][j]] %= MOD;
					}
					if (j > 1) {
						dp[i & 1][j][k / A[i][j]] += dp[i & 1][j - 1][k];
						dp[i & 1][j][k / A[i][j]] %= MOD;
					}
				}
			}
		}
	for (int i : vec)
		ans = (ans + dp[R & 1][S][i]) % MOD;
	cout << ((sub - ans) % MOD + MOD) % MOD << '\n';
}

Compilation message (stderr)

mobitel.cpp:42:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   42 | main() {
      | ^~~~
mobitel.cpp: In function 'int main()':
mobitel.cpp:65:41: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
   65 |       dp[i & 1][j][k / A[i][j]] += dp[i & 1 ^ 1][j][k];
      |                                       ~~^~~

• Subtask 1: 26 / 130