답안 #656535

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
656535	2022-11-07T21:06:19 Z	prashant_th18	Mecho (IOI09_mecho)	C++17	100 / 100	502 ms	5980 KB

mecho

#ifdef LOCAL
	#define _GLIBCXX_DEBUG
#endif
#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
#define sz(s) ((int)s.size())
#define all(v) begin(v), end(v)
 
#ifdef LOCAL
	void debug_print(string s) {
		cerr << "\"" << s << "\"";
	}
 
	void debug_print(const char* s) {
		debug_print((string)s);
	}
 
	void debug_print(bool val) {
		cerr << (val ? "true" : "false");
	}
 
	void debug_print(int val) {
		cerr << val;
	}
 
	void debug_print(ll val) {
		cerr << val;
	}
 
	void debug_print(double val) {
		cerr << val;
	}
 
	template<typename F, typename S>
	void debug_print(pair<F, S> val) {
		cerr << "(";
		debug_print(val.first);
		cerr << ", ";
		debug_print(val.second);
		cerr << ")";
	}
 
	void debug_print(vector<bool> val) {
		cerr << "{";
		bool first = true;
		for (bool x : val) {
			if (!first) {
				cerr << ", ";
			} else {
				first = false;
			}
			debug_print(x);
		}
		cerr << "}";
	}
 
	template<typename T>
	void debug_print(T val) {
		cerr << "{";
		bool first = true;
		for (const auto &x : val) {
			if (!first) {
				cerr << ", ";
			} else {
				first = false;
			}
			debug_print(x);
		}
		cerr << "}";
	}
 
	void debug_print_collection() {
		cerr << endl;
	}
 
	template<typename First, typename... Args>
	void debug_print_collection(First val, Args... args) {
		cerr << " ";
		debug_print(val);
		debug_print_collection(args...);
	}
 
#define debug(...) cerr << "@@@ " << #__VA_ARGS__ << " ="; debug_print_collection(__VA_ARGS__);
 
#else
	#define debug(...) 
#endif
 
typedef long double ld;
const int MOD = 1000000007;
#define ff first
#define ss second
const int inf = (int)1e9;
 
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
using pll = pair<ll, ll>;
 
// *-> KISS*
int solve() {
    int n, s; cin >> n >> s;
	vector<string> v(n);
	for(int i = 0; i < n; ++i) cin >> v[i];
	pll start;
	vector<pll> bees;
	for(int i = 0; i < n; ++i) {
		for(int j = 0; j < n; ++j) {
			if(v[i][j] == 'M') start = {i, j};
			else if(v[i][j] == 'H') bees.push_back({i, j});
		}
	}
	// Valid function for mecho
	auto mvalid = [&](int i, int j) {
		return i >= 0 && j >= 0 && i < n && j < n && v[i][j] != 'T';
	};
	// valid function for bees
	auto bvalid = [&](int i, int j) {
		return i >= 0 && j >= 0 && i < n && j < n && v[i][j] != 'T' && v[i][j] != 'D';
	};
 
	int dx[] = {-1, 0, 1, 0};
	int dy[] = {0, 1, 0, -1};
 
	int ans = -1;
	int si = 0, ei = 1000000;
	while(si <= ei) {
		int mid = (si + ei) >> 1;
		// We are assuming that Mecho will stay at it's place for mid minutes and then start moving towards 
		// his home
		vector<vector<bool>> bvis(n, vector<bool>(n, false)), 
			mvis(n, vector<bool>(n, false));
	
		vector<pll> last;
		vector<vector<int>> steps(n, vector<int>(n, inf));
		{
			queue<array<ll, 3>> q;
			for(int i = 0; i < sz(bees); ++i) {
				q.push({bees[i].ff, bees[i].ss, 0});
				bvis[bees[i].ff][bees[i].ss] = true;
			}
			while(!q.empty()) {
				array<ll, 3> t = q.front(); q.pop();
				steps[t[0]][t[1]] = 0;
				if(t[2] == mid) {
					last.push_back({t[0], t[1]});
					continue;
				}
 
				int x = t[0], y = t[1], step = t[2];
 
				for(int i = 0; i < 4; ++i) {
					int ni = x + dx[i], nj = y + dy[i];
					if(bvalid(ni, nj) && !bvis[ni][nj]) {
						bvis[ni][nj] = true;
						q.push({ni, nj, step + 1});
					}
				}
			}
		}
		queue<array<ll, 3>> q;
		for(int i = 0; i < sz(last); ++i) {
			q.push({last[i].ff, last[i].ss, 0});
		}
		while(!q.empty()) {
			array<ll, 3> _ = q.front(); q.pop();
			int x = _[0], y = _[1], step = _[2];
			steps[x][y] = step * s;
			for(int i = 0; i < 4; ++i) {
				int ni = x + dx[i], nj = y + dy[i];
				if(bvalid(ni, nj) && !bvis[ni][nj]) {
					q.push({ni, nj, step + 1});
					bvis[ni][nj] = true;
				}
			}
		}
		/* debug(steps); */
		/* q = queue<array<ll, 3>> (); */
		while(!q.empty()) q.pop();
 
		if(steps[start.ff][start.ss] != 0) q.push({start.ff, start.ss, 0LL});
		mvis[start.ff][start.ss] = true;
		ll minutes = -1; // -1 means unreachability
		while(!q.empty()) {
			array<ll, 3> t = q.front(); q.pop();
			int x = t[0], y = t[1], step = t[2];
			if(v[x][y] == 'D') {
				minutes = step;
				break;
			}
 
			for(int i = 0; i < 4; ++i) {
				int ni = x + dx[i], nj = y + dy[i];
				if(mvalid(ni, nj) && !mvis[ni][nj] && steps[ni][nj] > (step + 1)) {
					mvis[ni][nj] = true;
					q.push({ni, nj, step + 1});
				}
			}
		}
 
		if(minutes != -1) {
			ans = mid; si = mid + 1;
		}
		else ei = mid - 1;
	}
	cout << ans;
	return 0;
}
int32_t main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    bool test = false;
	int TET = 1;
    if(test) cin >> TET;
    cout << fixed << setprecision(6);
    for (int i = 1; i <= TET; i++) {
		#ifdef LOCAL
        	cout << "##################" << '\n';
		#endif
 
        if (solve()) {
            break;
        }
        cout << '\n';
    }
	#ifdef LOCAL
    	cout << endl << "finished in " << clock() * 1.0 / CLOCKS_PER_SEC << " sec" << endl;
	#endif
	return 0;
}
// -> Keep It Simple Stupid!

Subtask #1

100.0 / 100.0

#	결과	실행 시간	메모리	Grader output
1	Correct	0 ms	212 KB	Output is correct
2	Correct	0 ms	212 KB	Output is correct
3	Correct	0 ms	212 KB	Output is correct
4	Correct	0 ms	212 KB	Output is correct
5	Correct	0 ms	212 KB	Output is correct
6	Correct	0 ms	212 KB	Output is correct
7	Correct	405 ms	4512 KB	Output is correct
8	Correct	1 ms	212 KB	Output is correct
9	Correct	1 ms	212 KB	Output is correct
10	Correct	1 ms	212 KB	Output is correct
11	Correct	1 ms	212 KB	Output is correct
12	Correct	2 ms	340 KB	Output is correct
13	Correct	3 ms	340 KB	Output is correct
14	Correct	3 ms	340 KB	Output is correct
15	Correct	0 ms	212 KB	Output is correct
16	Correct	1 ms	212 KB	Output is correct
17	Correct	1 ms	212 KB	Output is correct
18	Correct	1 ms	212 KB	Output is correct
19	Correct	1 ms	212 KB	Output is correct
20	Correct	1 ms	212 KB	Output is correct
21	Correct	1 ms	340 KB	Output is correct
22	Correct	1 ms	340 KB	Output is correct
23	Correct	1 ms	340 KB	Output is correct
24	Correct	1 ms	340 KB	Output is correct
25	Correct	2 ms	356 KB	Output is correct
26	Correct	2 ms	340 KB	Output is correct
27	Correct	2 ms	340 KB	Output is correct
28	Correct	2 ms	340 KB	Output is correct
29	Correct	2 ms	368 KB	Output is correct
30	Correct	2 ms	340 KB	Output is correct
31	Correct	2 ms	340 KB	Output is correct
32	Correct	2 ms	340 KB	Output is correct
33	Correct	36 ms	1028 KB	Output is correct
34	Correct	34 ms	1076 KB	Output is correct
35	Correct	64 ms	1028 KB	Output is correct
36	Correct	46 ms	1224 KB	Output is correct
37	Correct	41 ms	1236 KB	Output is correct
38	Correct	82 ms	1236 KB	Output is correct
39	Correct	57 ms	1444 KB	Output is correct
40	Correct	52 ms	1492 KB	Output is correct
41	Correct	101 ms	1476 KB	Output is correct
42	Correct	75 ms	1816 KB	Output is correct
43	Correct	67 ms	1728 KB	Output is correct
44	Correct	131 ms	1724 KB	Output is correct
45	Correct	87 ms	1972 KB	Output is correct
46	Correct	84 ms	1980 KB	Output is correct
47	Correct	162 ms	2008 KB	Output is correct
48	Correct	102 ms	2308 KB	Output is correct
49	Correct	91 ms	2312 KB	Output is correct
50	Correct	190 ms	2344 KB	Output is correct
51	Correct	121 ms	2656 KB	Output is correct
52	Correct	106 ms	2644 KB	Output is correct
53	Correct	217 ms	2644 KB	Output is correct
54	Correct	144 ms	2988 KB	Output is correct
55	Correct	134 ms	3004 KB	Output is correct
56	Correct	257 ms	3020 KB	Output is correct
57	Correct	161 ms	3376 KB	Output is correct
58	Correct	144 ms	3384 KB	Output is correct
59	Correct	297 ms	3432 KB	Output is correct
60	Correct	173 ms	3796 KB	Output is correct
61	Correct	160 ms	3784 KB	Output is correct
62	Correct	344 ms	3836 KB	Output is correct
63	Correct	443 ms	3796 KB	Output is correct
64	Correct	502 ms	3820 KB	Output is correct
65	Correct	488 ms	3812 KB	Output is correct
66	Correct	481 ms	3804 KB	Output is correct
67	Correct	428 ms	3800 KB	Output is correct
68	Correct	418 ms	4000 KB	Output is correct
69	Correct	436 ms	4032 KB	Output is correct
70	Correct	405 ms	3992 KB	Output is correct
71	Correct	406 ms	3892 KB	Output is correct
72	Correct	396 ms	3796 KB	Output is correct
73	Correct	403 ms	5980 KB	Output is correct
74	Correct	387 ms	4664 KB	Output is correct
75	Correct	403 ms	4888 KB	Output is correct
76	Correct	392 ms	4636 KB	Output is correct
77	Correct	407 ms	4840 KB	Output is correct
78	Correct	381 ms	5284 KB	Output is correct
79	Correct	392 ms	4736 KB	Output is correct
80	Correct	384 ms	4564 KB	Output is correct
81	Correct	403 ms	4676 KB	Output is correct
82	Correct	364 ms	4564 KB	Output is correct
83	Correct	444 ms	5112 KB	Output is correct
84	Correct	407 ms	4420 KB	Output is correct
85	Correct	422 ms	4436 KB	Output is correct
86	Correct	411 ms	4720 KB	Output is correct
87	Correct	418 ms	4436 KB	Output is correct
88	Correct	428 ms	4864 KB	Output is correct
89	Correct	411 ms	4300 KB	Output is correct
90	Correct	424 ms	4908 KB	Output is correct
91	Correct	418 ms	4288 KB	Output is correct
92	Correct	428 ms	5064 KB	Output is correct