Submission #1103071

# Submission time Handle Problem Language Result Execution time Memory
1103071 2024-10-19T22:40:19 Z ef10 Mecho (IOI09_mecho) C++17
53 / 100
119 ms 8440 KB
// Source: https://usaco.guide/general/io

#include <bits/stdc++.h>
using namespace std;

int N,S;
string M[1001];
struct node {
	int hd;
	int md;
};
bool v[1001][1001];
node all[1001][1001];
pair<int,int> m;

bool work(int e) {
	for (int i = 0; i < N; i++) {
		for (int j = 0; j < N; j++) {
			all[i][j].md = -1;
		}
	}

	queue<pair<int,int> > q;
	q.push(m);
	all[m.first][m.second].md = 0;
	if (all[m.first][m.second].hd != -1 && all[m.first][m.second].hd <= e) return false;
	while (!q.empty()) {
		auto c = q.front();
						//cout << "handling " << c.first << "/" << c.second << "/" << all[c.first][c.second].md << endl;
		int cost = all[c.first][c.second].md+1;
		q.pop();
			for (auto i : {-1,1}) {
				for (int j = 0; j <= 1; j++) {
					int ti = j ? c.first : c.first+i;
					int tj = j ? c.second+i : c.second;
					if (ti < 0 || ti >= N || tj < 0 || tj >= N) continue;
					//cout << "          " << ti << "/" << tj << " " << endl;
					if (M[ti][tj] == 'T') continue;
					if (all[ti][tj].md >= 0 && all[ti][tj].md <= cost) continue;
					if (all[ti][tj].hd >= 0 && all[ti][tj].hd <= cost/S+e) continue;
					if (M[ti][tj] == 'D') return true;
					//cout << "          " << ti << "/" << tj << " passed" << endl;
					all[ti][tj].md = cost;
						q.push(make_pair(ti,tj));
						//cout << "       add q " << ti << "/" << tj << "/" << cost << endl;
				}
			}
		/*for (int i = 0; i < N; i++) {
			for (int j = 0; j < N; j++) {
				cout << all[i][j].md << " ";
			}
			cout << endl;
		}*/
	}
	return false;
}

int solve() {
	int lo = 0, hi = 2*N;
		// if none of the values in the range work, return lo - 1
	lo--;
	while (lo < hi) {
		// find the middle of the current range (rounding up)
		int mid = lo + (hi - lo + 1) / 2;
		//cout << "mid: " << mid << ", " << lo << "/" << hi << endl;
		if (work(mid)) {
			//cout << " worked" << endl;
			// if mid works, then all numbers smaller than mid also work
			lo = mid;
		} else {
			//cout << " not work" << endl;
			// if mid does not work, greater values would not work either
			hi = mid - 1;
		}
	}
	return lo;
}

int main() {
	cin >> N >> S;
	for (int i = 0; i < N; i++) {
		for (int j = 0; j < N; j++) {
			all[i][j].hd = -1;
		}
	}
	queue<pair<int,int> > q;
	for (int i = 0; i < N; i++) {
		cin >> M[i];
		for (int j = 0; j < N; j++) {
			if (M[i][j] == 'H') {
				all[i][j].hd = 0;
				q.push(make_pair(i,j));
			} else if (M[i][j] == 'M') {
				m = make_pair(i,j);
			}
		}
	}
	while (!q.empty()) {
		auto c = q.front();
		int cost = all[c.first][c.second].hd+1;
		q.pop();
		for (auto i : {-1,1}) {
			for (int j = 0; j <= 1; j++) {
				int ti = j ? c.first : c.first+i;
				int tj = j ? c.second+i : c.second;
				if (ti < 0 || ti >= N || tj < 0 || tj >= N) continue;
				if (M[ti][tj]=='T' || M[ti][tj]=='D' || (all[ti][tj].hd!=-1 && all[ti][tj].hd<=cost)) continue;
				all[ti][tj].hd = cost;
				q.push(make_pair(ti,tj));
				//cout << "add " << ti << "/" << tj << endl;
			}
		}
	}
	/*for (int i = 0; i < N; i++) {
		for (int j = 0; j < N; j++) {
			cout << all[i][j].hd << " ";
		}
		cout << endl;
	}*/
	int r = solve();
	cout << r << endl;
	//cout << work(3) << endl;
}
# Verdict Execution time Memory Grader output
1 Correct 1 ms 336 KB Output is correct
2 Correct 1 ms 336 KB Output is correct
3 Correct 1 ms 336 KB Output is correct
4 Correct 1 ms 512 KB Output is correct
5 Correct 1 ms 336 KB Output is correct
6 Correct 1 ms 336 KB Output is correct
7 Correct 69 ms 7504 KB Output is correct
8 Correct 1 ms 336 KB Output is correct
9 Correct 1 ms 336 KB Output is correct
10 Correct 1 ms 336 KB Output is correct
11 Correct 1 ms 336 KB Output is correct
12 Incorrect 1 ms 2384 KB Output isn't correct
13 Correct 1 ms 2640 KB Output is correct
14 Correct 1 ms 2384 KB Output is correct
15 Incorrect 1 ms 336 KB Output isn't correct
16 Incorrect 1 ms 336 KB Output isn't correct
17 Incorrect 1 ms 2384 KB Output isn't correct
18 Incorrect 1 ms 2384 KB Output isn't correct
19 Incorrect 1 ms 2384 KB Output isn't correct
20 Incorrect 1 ms 2384 KB Output isn't correct
21 Incorrect 1 ms 2384 KB Output isn't correct
22 Incorrect 1 ms 2384 KB Output isn't correct
23 Incorrect 1 ms 2384 KB Output isn't correct
24 Incorrect 1 ms 2384 KB Output isn't correct
25 Incorrect 1 ms 2556 KB Output isn't correct
26 Incorrect 1 ms 2384 KB Output isn't correct
27 Incorrect 1 ms 2392 KB Output isn't correct
28 Incorrect 1 ms 2384 KB Output isn't correct
29 Incorrect 1 ms 2640 KB Output isn't correct
30 Incorrect 1 ms 2640 KB Output isn't correct
31 Incorrect 1 ms 2640 KB Output isn't correct
32 Incorrect 1 ms 2640 KB Output isn't correct
33 Incorrect 5 ms 4688 KB Output isn't correct
34 Incorrect 5 ms 4944 KB Output isn't correct
35 Correct 13 ms 4904 KB Output is correct
36 Incorrect 6 ms 4688 KB Output isn't correct
37 Incorrect 6 ms 4856 KB Output isn't correct
38 Correct 18 ms 4932 KB Output is correct
39 Incorrect 8 ms 4944 KB Output isn't correct
40 Incorrect 7 ms 4944 KB Output isn't correct
41 Correct 25 ms 4944 KB Output is correct
42 Incorrect 11 ms 5236 KB Output isn't correct
43 Incorrect 9 ms 5232 KB Output isn't correct
44 Correct 29 ms 5200 KB Output is correct
45 Incorrect 12 ms 7248 KB Output isn't correct
46 Incorrect 11 ms 7504 KB Output isn't correct
47 Correct 35 ms 7248 KB Output is correct
48 Incorrect 13 ms 7248 KB Output isn't correct
49 Incorrect 12 ms 7248 KB Output isn't correct
50 Correct 42 ms 7732 KB Output is correct
51 Incorrect 15 ms 7712 KB Output isn't correct
52 Incorrect 14 ms 7248 KB Output isn't correct
53 Correct 60 ms 7504 KB Output is correct
54 Incorrect 17 ms 7248 KB Output isn't correct
55 Incorrect 15 ms 7248 KB Output isn't correct
56 Correct 59 ms 7760 KB Output is correct
57 Incorrect 18 ms 7504 KB Output isn't correct
58 Incorrect 19 ms 7504 KB Output isn't correct
59 Correct 68 ms 8080 KB Output is correct
60 Incorrect 22 ms 8016 KB Output isn't correct
61 Incorrect 19 ms 7680 KB Output isn't correct
62 Correct 76 ms 8180 KB Output is correct
63 Correct 84 ms 7504 KB Output is correct
64 Correct 119 ms 7516 KB Output is correct
65 Correct 119 ms 7504 KB Output is correct
66 Correct 91 ms 7504 KB Output is correct
67 Correct 88 ms 7504 KB Output is correct
68 Correct 47 ms 7600 KB Output is correct
69 Correct 38 ms 7420 KB Output is correct
70 Correct 37 ms 7504 KB Output is correct
71 Correct 37 ms 8016 KB Output is correct
72 Correct 30 ms 7504 KB Output is correct
73 Correct 34 ms 7760 KB Output is correct
74 Correct 43 ms 7928 KB Output is correct
75 Correct 47 ms 8272 KB Output is correct
76 Correct 59 ms 7760 KB Output is correct
77 Correct 49 ms 7760 KB Output is correct
78 Correct 54 ms 7776 KB Output is correct
79 Correct 45 ms 8272 KB Output is correct
80 Correct 52 ms 7760 KB Output is correct
81 Correct 53 ms 7760 KB Output is correct
82 Correct 46 ms 7772 KB Output is correct
83 Correct 59 ms 7772 KB Output is correct
84 Correct 57 ms 7768 KB Output is correct
85 Correct 55 ms 7760 KB Output is correct
86 Correct 59 ms 7760 KB Output is correct
87 Correct 58 ms 8292 KB Output is correct
88 Correct 66 ms 7504 KB Output is correct
89 Correct 60 ms 8440 KB Output is correct
90 Correct 63 ms 8240 KB Output is correct
91 Correct 69 ms 7504 KB Output is correct
92 Correct 57 ms 8016 KB Output is correct