oj.uz

Submission #329367

# Submission time Handle Problem Language Result Execution time Memory
329367 2020-11-20T19:45:06 Z rqi Mecho (IOI09_mecho) C++14
100 / 100
 210 ms 12396 KB 
#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef long double ld;
typedef double db; 
typedef string str; 

typedef pair<int,int> pi;
typedef pair<ll,ll> pl; 
typedef pair<db,db> pd; 

typedef vector<int> vi; 
typedef vector<bool> vb; 
typedef vector<ll> vl; 
typedef vector<db> vd; 
typedef vector<str> vs; 
typedef vector<pi> vpi;
typedef vector<pl> vpl; 
typedef vector<pd> vpd; 

#define mp make_pair
#define f first
#define s second
#define sz(x) (int)(x).size()
#define all(x) begin(x), end(x)
#define rall(x) (x).rbegin(), (x).rend() 
#define sor(x) sort(all(x)) 
#define rsz resize
#define ins insert 
#define ft front() 
#define bk back()
#define pf push_front 
#define pb push_back
#define eb emplace_back 
#define lb lower_bound 
#define ub upper_bound 

#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)

const int MOD = 1e9+7; // 998244353;
const int MX = 2e5+5; 
const ll INF = 1e18; 
const ld PI = acos((ld)-1);
const int xd[4] = {1,0,-1,0}, yd[4] = {0,1,0,-1}; 
mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count()); 

template<class T> bool ckmin(T& a, const T& b) { 
	return b < a ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { 
	return a < b ? a = b, 1 : 0; } 
constexpr int pct(int x) { return __builtin_popcount(x); } 
constexpr int bits(int x) { return 31-__builtin_clz(x); } // floor(log2(x)) 
ll cdiv(ll a, ll b) { return a/b+((a^b)>0&&a%b); } // divide a by b rounded up
ll fdiv(ll a, ll b) { return a/b-((a^b)<0&&a%b); } // divide a by b rounded down
ll half(ll x) { return fdiv(x,2); }

template<class T, class U> T fstTrue(T lo, T hi, U f) { 
	// note: if (lo+hi)/2 is used instead of half(lo+hi) then this will loop infinitely when lo=hi
	hi ++; assert(lo <= hi); // assuming f is increasing
	while (lo < hi) { // find first index such that f is true 
		T mid = half(lo+hi);
		f(mid) ? hi = mid : lo = mid+1; 
	} 
	return lo;
}
template<class T, class U> T lstTrue(T lo, T hi, U f) {
	lo --; assert(lo <= hi); // assuming f is decreasing
	while (lo < hi) { // find first index such that f is true 
		T mid = half(lo+hi+1);
		f(mid) ? lo = mid : hi = mid-1;
	} 
	return lo;
}
template<class T> void remDup(vector<T>& v) { 
	sort(all(v)); v.erase(unique(all(v)),end(v)); }

// INPUT
template<class A> void re(complex<A>& c);
template<class A, class B> void re(pair<A,B>& p);
template<class A> void re(vector<A>& v);
template<class A, size_t SZ> void re(array<A,SZ>& a);

template<class T> void re(T& x) { cin >> x; }
void re(db& d) { str t; re(t); d = stod(t); }
void re(ld& d) { str t; re(t); d = stold(t); }
template<class H, class... T> void re(H& h, T&... t) { re(h); re(t...); }

template<class A> void re(complex<A>& c) { A a,b; re(a,b); c = {a,b}; }
template<class A, class B> void re(pair<A,B>& p) { re(p.f,p.s); }
template<class A> void re(vector<A>& x) { trav(a,x) re(a); }
template<class A, size_t SZ> void re(array<A,SZ>& x) { trav(a,x) re(a); }

// TO_STRING
#define ts to_string
str ts(char c) { return str(1,c); }
str ts(const char* s) { return (str)s; }
str ts(str s) { return s; }
str ts(bool b) { 
	#ifdef LOCAL
		return b ? "true" : "false"; 
	#else 
		return ts((int)b);
	#endif
}
template<class A> str ts(complex<A> c) { 
	stringstream ss; ss << c; return ss.str(); }
str ts(vector<bool> v) {
	str res = "{"; F0R(i,sz(v)) res += char('0'+v[i]);
	res += "}"; return res; }
template<size_t SZ> str ts(bitset<SZ> b) {
	str res = ""; F0R(i,SZ) res += char('0'+b[i]);
	return res; }
template<class A, class B> str ts(pair<A,B> p);
template<class T> str ts(T v) { // containers with begin(), end()
	#ifdef LOCAL
		bool fst = 1; str res = "{";
		for (const auto& x: v) {
			if (!fst) res += ", ";
			fst = 0; res += ts(x);
		}
		res += "}"; return res;
	#else
		bool fst = 1; str res = "";
		for (const auto& x: v) {
			if (!fst) res += " ";
			fst = 0; res += ts(x);
		}
		return res;

	#endif
}
template<class A, class B> str ts(pair<A,B> p) {
	#ifdef LOCAL
		return "("+ts(p.f)+", "+ts(p.s)+")"; 
	#else
		return ts(p.f)+" "+ts(p.s);
	#endif
}

// OUTPUT
template<class A> void pr(A x) { cout << ts(x); }
template<class H, class... T> void pr(const H& h, const T&... t) { 
	pr(h); pr(t...); }
void ps() { pr("\n"); } // print w/ spaces
template<class H, class... T> void ps(const H& h, const T&... t) { 
	pr(h); if (sizeof...(t)) pr(" "); ps(t...); }

// DEBUG
void DBG() { cerr << "]" << endl; }
template<class H, class... T> void DBG(H h, T... t) {
	cerr << ts(h); if (sizeof...(t)) cerr << ", ";
	DBG(t...); }
#ifdef LOCAL // compile with -DLOCAL, chk -> fake assert
	#define dbg(...) cerr << "Line(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
	#define chk(...) if (!(__VA_ARGS__)) cerr << "Line(" << __LINE__ << ") -> function(" \
		 << __FUNCTION__  << ") -> CHK FAILED: (" << #__VA_ARGS__ << ")" << "\n", exit(0);
#else
	#define dbg(...) 0
	#define chk(...) 0
#endif

// FILE I/O
void setIn(str s) { freopen(s.c_str(),"r",stdin); }
void setOut(str s) { freopen(s.c_str(),"w",stdout); }
void unsyncIO() { cin.tie(0)->sync_with_stdio(0); }
void setIO(str s = "") {
	unsyncIO();
	// cin.exceptions(cin.failbit); 
	// throws exception when do smth illegal
	// ex. try to read letter into int
	if (sz(s)) { setIn(s+".in"), setOut(s+".out"); } // for USACO
}

const int mx = 805;
int N;
ll S;
bool bearclose[mx][mx]; //closed to the bear
bool beeclose[mx][mx];
vpi hives;
pi pstart, pend;
ll bdist[mx][mx];

void genBeeDists(){
	for(int i = 1; i <= N; i++){
		for(int j = 1; j <= N; j++){
			bdist[i][j] = INF;
		}
	}

	queue<pair<ll, pi>> q;

	for(auto u: hives){
		bdist[u.f][u.s] = 0;
		q.push(mp(0, u));
	}
	
	while(sz(q)){
		ll dist = q.front().f;
		pi pos = q.front().s;
		q.pop();
		for(int d = 0; d < 4; d++){
			if(beeclose[pos.f+xd[d]][pos.s+yd[d]]) continue;
			if(bdist[pos.f+xd[d]][pos.s+yd[d]] <= dist+1) continue;
			bdist[pos.f+xd[d]][pos.s+yd[d]] = dist+1;
			q.push(mp(dist+1, mp(pos.f+xd[d], pos.s+yd[d])));
		}
	}

}

ll ctim[mx][mx];

bool works(ll wait){
	for(int i = 1; i <= N; i++){
		for(int j = 1; j <= N; j++){
			ctim[i][j] = INF;
		}
	}

	queue<pair<ll, pi>> q;
	if(bdist[pstart.f][pstart.s] == INF || wait*S >= ll(S)*ll(bdist[pstart.f][pstart.s])) return 0;
	q.push(mp(wait*S, pstart));
	while(sz(q)){
		ll dist = q.front().f;
		pi pos = q.front().s;
		q.pop();
		// if(wait == 2){
		// 	dbg(pos);
		// }
		if(pos == pend) return 1;

		for(int d = 0; d < 4; d++){
			if(bearclose[pos.f+xd[d]][pos.s+yd[d]]) continue;
			if(ctim[pos.f+xd[d]][pos.s+yd[d]] <= dist+1) continue;
			if(bdist[pos.f+xd[d]][pos.s+yd[d]] != INF && dist+1 >= ll(S)*ll(bdist[pos.f+xd[d]][pos.s+yd[d]])) continue;
			ctim[pos.f+xd[d]][pos.s+yd[d]] = dist+1;
			q.push(mp(dist+1, mp(pos.f+xd[d], pos.s+yd[d])));
		}
	}

	return 0;
}

int main() {
	setIO();
	cin >> N >> S;
	
	for(int i = 1; i <= N; i++){
		string s;
		cin >> s;
		for(int j = 0; j < N; j++){
			if(s[j] == 'T'){
				bearclose[i][j+1] = 1;
				beeclose[i][j+1] = 1;
			}
			else if(s[j] == 'G'){

			}
			else if(s[j] == 'M'){
				pstart = mp(i, j+1);
			}
			else if(s[j] == 'D'){
				beeclose[i][j+1] = 1;
				pend = mp(i, j+1);
			}
			else if(s[j] == 'H'){
				bearclose[i][j+1] = 1;
				hives.pb(mp(i, j+1));
			}
		}
	}

	for(int i = 0; i <= N+1; i++){
		bearclose[i][0] = 1;
		bearclose[i][N+1] = 1;
		bearclose[0][i] = 1;
		bearclose[N+1][i] = 1;
		beeclose[i][0] = 1;
		beeclose[i][N+1] = 1;
		beeclose[0][i] = 1;
		beeclose[N+1][i] = 1;
	}

	genBeeDists();

	// for(int i = 1; i <= N; i++){
	// 	for(int j = 1; j <= N; j++){
	// 		cout << bdist[i][j] << " ";
	// 	}
	// 	cout << "\n";
	// }

	ll lo = -1;
	ll hi = mx*mx;

	while(lo < hi){
		ll mid;
		if(lo+hi >= 0){
			mid = (lo+hi)/2+1;
		}
		else{
			mid = 0;
		}

		if(works(mid)){
			lo = mid;
		}
		else hi = mid-1;

		// opo++;
		// if(opo >= 100){
		// 	assert(0==1);
		// }
	}

	ps(lo);

	// you should actually read the stuff at the bottom
}

/* stuff you should look for
	* int overflow, array bounds
	* special cases (n=1?)
	* do smth instead of nothing and stay organized
	* WRITE STUFF DOWN
*/

Compilation message

mecho.cpp: In function 'void setIn(str)':
mecho.cpp:168:28: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  168 | void setIn(str s) { freopen(s.c_str(),"r",stdin); }
      |                     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
mecho.cpp: In function 'void setOut(str)':
mecho.cpp:169:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  169 | void setOut(str s) { freopen(s.c_str(),"w",stdout); }
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 364 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Correct 1 ms 364 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 0 ms 492 KB Output is correct
6 Correct 1 ms 492 KB Output is correct
7 Correct 118 ms 12012 KB Output is correct
8 Correct 1 ms 492 KB Output is correct
9 Correct 1 ms 492 KB Output is correct
10 Correct 1 ms 492 KB Output is correct
11 Correct 1 ms 492 KB Output is correct
12 Correct 1 ms 1004 KB Output is correct
13 Correct 1 ms 876 KB Output is correct
14 Correct 1 ms 1004 KB Output is correct
15 Correct 1 ms 620 KB Output is correct
16 Correct 1 ms 620 KB Output is correct
17 Correct 1 ms 620 KB Output is correct
18 Correct 1 ms 620 KB Output is correct
19 Correct 1 ms 620 KB Output is correct
20 Correct 1 ms 620 KB Output is correct
21 Correct 1 ms 748 KB Output is correct
22 Correct 1 ms 748 KB Output is correct
23 Correct 1 ms 876 KB Output is correct
24 Correct 1 ms 876 KB Output is correct
25 Correct 1 ms 1004 KB Output is correct
26 Correct 1 ms 1004 KB Output is correct
27 Correct 1 ms 1004 KB Output is correct
28 Correct 1 ms 1004 KB Output is correct
29 Correct 1 ms 1132 KB Output is correct
30 Correct 1 ms 1132 KB Output is correct
31 Correct 1 ms 1132 KB Output is correct
32 Correct 1 ms 1132 KB Output is correct
33 Correct 6 ms 5356 KB Output is correct
34 Correct 6 ms 5356 KB Output is correct
35 Correct 29 ms 5356 KB Output is correct
36 Correct 7 ms 5996 KB Output is correct
37 Correct 7 ms 5996 KB Output is correct
38 Correct 40 ms 6124 KB Output is correct
39 Correct 9 ms 6764 KB Output is correct
40 Correct 9 ms 6764 KB Output is correct
41 Correct 47 ms 6764 KB Output is correct
42 Correct 10 ms 7532 KB Output is correct
43 Correct 11 ms 7532 KB Output is correct
44 Correct 60 ms 7660 KB Output is correct
45 Correct 12 ms 8172 KB Output is correct
46 Correct 12 ms 8172 KB Output is correct
47 Correct 83 ms 8172 KB Output is correct
48 Correct 14 ms 8940 KB Output is correct
49 Correct 14 ms 8940 KB Output is correct
50 Correct 94 ms 8940 KB Output is correct
51 Correct 21 ms 9580 KB Output is correct
52 Correct 15 ms 9580 KB Output is correct
53 Correct 117 ms 9580 KB Output is correct
54 Correct 17 ms 10348 KB Output is correct
55 Correct 19 ms 10348 KB Output is correct
56 Correct 143 ms 10476 KB Output is correct
57 Correct 20 ms 10988 KB Output is correct
58 Correct 20 ms 10988 KB Output is correct
59 Correct 169 ms 11104 KB Output is correct
60 Correct 21 ms 11756 KB Output is correct
61 Correct 22 ms 11756 KB Output is correct
62 Correct 191 ms 11884 KB Output is correct
63 Correct 139 ms 11756 KB Output is correct
64 Correct 210 ms 11756 KB Output is correct
65 Correct 196 ms 11756 KB Output is correct
66 Correct 149 ms 11756 KB Output is correct
67 Correct 153 ms 11884 KB Output is correct
68 Correct 68 ms 12012 KB Output is correct
69 Correct 56 ms 11884 KB Output is correct
70 Correct 51 ms 11756 KB Output is correct
71 Correct 48 ms 11756 KB Output is correct
72 Correct 40 ms 11756 KB Output is correct
73 Correct 43 ms 12268 KB Output is correct
74 Correct 77 ms 12396 KB Output is correct
75 Correct 84 ms 12152 KB Output is correct
76 Correct 74 ms 12268 KB Output is correct
77 Correct 81 ms 12268 KB Output is correct
78 Correct 112 ms 12268 KB Output is correct
79 Correct 60 ms 12268 KB Output is correct
80 Correct 81 ms 12396 KB Output is correct
81 Correct 94 ms 12268 KB Output is correct
82 Correct 76 ms 12268 KB Output is correct
83 Correct 111 ms 12140 KB Output is correct
84 Correct 91 ms 12140 KB Output is correct
85 Correct 90 ms 12140 KB Output is correct
86 Correct 93 ms 12016 KB Output is correct
87 Correct 97 ms 12088 KB Output is correct
88 Correct 113 ms 12012 KB Output is correct
89 Correct 104 ms 12012 KB Output is correct
90 Correct 107 ms 12012 KB Output is correct
91 Correct 121 ms 12012 KB Output is correct
92 Correct 110 ms 12012 KB Output is correct