Submission #389432

#	Time	Username	Problem	Language	Result	Execution time	Memory
389432		arwaeystoamneg	Mecho (IOI09_mecho)	C++17	54 / 100	253 ms	8848 KiB

mecho

// EXPLOSION!
#define _CRT_SECURE_NO_WARNINGS
#include<bits/stdc++.h>
#include<unordered_set>
#include<unordered_map>
#include<chrono>

using namespace std;
typedef pair<int, int> pii;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pair<int, int>> vpi;
typedef vector<pair<ll, ll>> vpll;

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)

#define pb push_back
#define mp make_pair
#define rsz resize
#define sz(x) int(x.size())
#define all(x) x.begin(),x.end()
#define f first
#define s second
#define cont continue
#define endl '\n'
//#define ednl '\n'
#define test int testc;cin>>testc;while(testc--)
#define pr(a, b) trav(x,a)cerr << x << b; cerr << endl;
#define message cout << "Hello World" << endl;
const int dx[4] = { 1,0,-1,0 }, dy[4] = { 0,1,0,-1 }; // for every grid problem!!
const ll linf = 4000000000000000000LL;
const ll inf = 1000000007;//998244353    

void pv(vi a) { trav(x, a)cout << x << " "; cout << endl; }void pv(vll a) { trav(x, a)cout << x << " "; cout << endl; }void pv(vector<vi>a) {
	F0R(i, sz(a)) { cout << i << endl; pv(a[i]); cout << endl; }
}void pv(vector<vll>a) { F0R(i, sz(a)) { cout << i << endl; pv(a[i]); }cout << endl; }void pv(vector<string>a) { trav(x, a)cout << x << endl; cout << endl; }
void setIO(string s) {
	ios_base::sync_with_stdio(0); cin.tie(0);
	if (sz(s))
	{
		freopen((s + ".in").c_str(), "r", stdin);
		if (s != "test1")
			freopen((s + ".out").c_str(), "w", stdout);
	}
}

int n, m;
const int MAX = 805;
string a[MAX];
int dist[MAX][MAX];
int check(int i, int j)
{
	return i >= 0 && j >= 0 && i < n&& j < n&& a[i][j] != 'T';
}
struct T
{
	int d, extra;
	T next()
	{
		T t = (*this);
		t.extra--;
		if (t.extra == -1)
		{
			t.extra = m - 1;
			t.d++;
		}
		return t;
	}
	bool operator<(const T& x)const
	{
		if (d == x.d)return extra > x.extra;
		return d < x.d;
	}
};
T best[MAX][MAX];
T init = { inf,0 };
pii start, finish;
int solve(int t)
{
	F0R(i, n)F0R(j, n)best[i][j] = init;
	if (t >= dist[start.f][start.s])return 0;
	best[start.f][start.s] = { t,m };
	deque<pii>todo = { {start.f,start.s} };
	while (sz(todo))
	{
		int i = todo.back().f, j = todo.back().s;
		todo.pop_back();
		F0R(k, 4)
		{
			int x = i + dx[k], y = j + dy[k];
			if (check(x, y))
			{
				T temp = best[i][j];
				temp = temp.next();
				if (dist[x][y] > temp.d && temp < best[x][y])
				{
					best[x][y] = temp;
					todo.push_front({ x,y });
				}
			}
		}
	}
	return best[finish.f][finish.s].d != inf;
}
int main()
{
	setIO("");
	cin >> n >> m;
	F0R(i, n)cin >> a[i];
	F0R(i, n)
	{
		F0R(j, n)
		{
			if (a[i][j] == 'M')start = { i,j };
			if (a[i][j] == 'D')finish = { i,j };
		}
	}
	F0R(i, n)F0R(j, n)dist[i][j] = inf;
	deque<pii> todo;
	F0R(i, n)F0R(j, n)if (a[i][j] == 'H')todo.pb({ i,j }), dist[i][j] = 0;
	while (sz(todo))
	{
		int i = todo.back().f, j = todo.back().s;
		todo.pop_back();
		F0R(k, 4)
		{
			int x = i + dx[k], y = j + dy[k];
			if (check(x, y) && a[x][y] != 'D' && dist[x][y] > dist[i][j] + 1)
			{
				dist[x][y] = dist[i][j] + 1;
				todo.push_front({ x,y });
			}
		}
	}
	if (!solve(0))
	{
		cout << -1 << endl;
		return 0;
	}
	int l = 0, r = 2 * n * n;
	while (l < r)
	{
		int m = (l + r + 1) / 2;
		if (solve(m))
		{
			l = m;
		}
		else
		{
			r = m - 1;
		}
	}
	cout << l << endl;
}

Compilation message (stderr)

mecho.cpp: In function 'void setIO(std::string)':
mecho.cpp:48:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   48 |   freopen((s + ".in").c_str(), "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mecho.cpp:50:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   50 |    freopen((s + ".out").c_str(), "w", stdout);
      |    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 54 / 100