#include <bits/stdc++.h>
#define int long long
using namespace std;
int n,s;
vector<vector<int>> dist;
vector<vector<int>> grid;
pair<int,int> start;
pair<int,int> finish;
int debug=0;
int INF=1000000007;
int gval(pair<int,int> cell) {
return grid[cell.first][cell.second];
}
bool bounds(pair<int,int> cell) {
return 0<=cell.first && cell.first<n && 0<=cell.second && cell.second<n;
}
vector<pair<int,int>> getnei(pair<int,int> st) {
if (!(gval(st)==0 || gval(st)==3)) {
return {};
}
vector<pair<int,int>> V={{st.first-1,st.second},{st.first+1,st.second},{st.first,st.second+1},{st.first,st.second-1}};
vector<pair<int,int>> ans;
for (auto nei:V) {
if (bounds(nei) && ((gval(nei)==0) || gval(nei)==2)) {
ans.push_back(nei);
}
}
return ans;
}
bool BSTA(int time) {
//returns whether it can be done after waiting this time
vector<vector<int>> distance(n,vector<int>(n,INF));
vector<vector<int>> proc(n,vector<int>(n,0));
deque<pair<int,int>> visited={start};
distance[start.first][start.second] = 0;
while (visited.size()) {
pair<int,int> fi=visited[0];
visited.pop_front();
if (proc[fi.first][fi.second]) {
continue;
}
proc[fi.first][fi.second] = 1;
for (auto j:getnei(fi)) {
int bdist=time+(distance[fi.first][fi.second]+1)/s;
//it's the total number of steps the honey has to walk to reach this cell
if(debug) cout << fi.first << " " << fi.second << " " << j.first << " " << j.second << " "<<bdist << " " <<dist[fi.first][fi.second] << endl;
if (bdist>=(dist[j.first][j.second])) {
continue;
}
distance[j.first][j.second] = min(distance[j.first][j.second],distance[fi.first][fi.second]+1);
visited.push_back(j);
}
}
if(debug) cout << "BSTA TRYING METHOD CALCULATION TO FIND THE ANSWER" << " " << time << endl;
for (int i=0; i<n; i++) {
for (int j=0; j<n; j++) {
if(debug) cout << distance[i][j] <<" ";
}
if(debug) cout << endl;
}
return distance[finish.first][finish.second] < 3*n;
}
vector<pair<int,int>> adjlistbee(pair<int,int> st) {
if (!(gval(st)==0 || gval(st)==3)) {
return {};
}
vector<pair<int,int>> V={{st.first-1,st.second},{st.first+1,st.second},{st.first,st.second+1},{st.first,st.second-1}};
vector<pair<int,int>> ans;
for (auto nei:V) {
if (bounds(nei) && gval(nei)==0) {
ans.push_back(nei);
}
}
return ans;
}
signed main() {
if (debug) freopen("input.txt","r",stdin);
if (debug) freopen("output.txt","w",stdout);
cin >> n >> s;
dist=vector<vector<int>>(n,vector<int>(n,INF));
grid=vector<vector<int>>(n,vector<int>(n,-1));
vector<vector<int>> proc(n,vector<int>(n,0));
vector<pair<int,int>> hives;
deque<pair<int,int>> visited;
for (int i=0; i<n; i++) {
string st;
cin >> st;
//if(debug) cout << st << endl;
for (int j=0; j<n; j++) {
//if(debug) cout << i <<" " << j << " " << st[j] << endl;
int ans;
if (st[j]=='G') {
ans=0;
}
else if (st[j]=='M') {
ans=0;
start={i,j};
}
else if (st[j]=='D') {
ans=2;
finish={i,j};
}
else if (st[j]=='T') {
ans=1;
}
else {
//assert(st[j]=='H');
ans=3;
hives.push_back({i,j});
dist[i][j] = 0;
visited.push_back({i,j});
}
grid[i][j] = ans;
//if(debug) cout << i << " " << j << endl;
}
}
//a cell is available to bees if the cell is 0 or 3, 3 denotes starting hives
//a cell is available to mecho if the dist condition holds and the cell isn't a tree
while (visited.size()) {
pair<int,int> fi=visited[0];
visited.pop_front();
if (proc[fi.first][fi.second]) {
continue;
}
proc[fi.first][fi.second] = 1;
for (auto j:adjlistbee(fi)) {
dist[j.first][j.second] = min(dist[j.first][j.second],dist[fi.first][fi.second]+1);
visited.push_back(j);
}
}
if(debug) cout << "DISTS"<< endl;
for (int i=0; i<n; i++) {
for (int j=0; j<n; j++) {
//cout << dist[i][j] <<" ";
}
if(debug) cout << endl;
}
int l=0;
int r=n*3;
while (l<r) {
int m=(l+r)/2;
if (!BSTA(m)) {
l=l;
r=m;
}
else {
l=m+1;
r=r;
}
}
if (l==0 && !BSTA(l)) {
if(debug) cout << -1 << endl;
return 0;
}
while (l>0 && !BSTA(l)) {
l--;
}
while (BSTA(l+1)) {
l++;
}
if (l==0 && !BSTA(l)) {
if(debug) cout << -1 << endl;
return 0;
}
cout << l << endl;
}
Compilation message
mecho.cpp: In function 'int main()':
mecho.cpp:86:23: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
86 | if (debug) freopen("input.txt","r",stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
mecho.cpp:87:23: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
87 | if (debug) freopen("output.txt","w",stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
344 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Correct |
592 ms |
25700 KB |
Output is correct |
8 |
Incorrect |
1 ms |
348 KB |
Output isn't correct |
9 |
Correct |
0 ms |
348 KB |
Output is correct |
10 |
Correct |
0 ms |
600 KB |
Output is correct |
11 |
Correct |
0 ms |
348 KB |
Output is correct |
12 |
Execution timed out |
1051 ms |
344 KB |
Time limit exceeded |
13 |
Incorrect |
1 ms |
348 KB |
Output isn't correct |
14 |
Incorrect |
3 ms |
348 KB |
Output isn't correct |
15 |
Correct |
1 ms |
600 KB |
Output is correct |
16 |
Correct |
1 ms |
348 KB |
Output is correct |
17 |
Correct |
3 ms |
344 KB |
Output is correct |
18 |
Correct |
1 ms |
348 KB |
Output is correct |
19 |
Correct |
5 ms |
400 KB |
Output is correct |
20 |
Correct |
4 ms |
348 KB |
Output is correct |
21 |
Correct |
15 ms |
348 KB |
Output is correct |
22 |
Correct |
8 ms |
504 KB |
Output is correct |
23 |
Correct |
35 ms |
348 KB |
Output is correct |
24 |
Correct |
21 ms |
344 KB |
Output is correct |
25 |
Correct |
76 ms |
348 KB |
Output is correct |
26 |
Correct |
57 ms |
580 KB |
Output is correct |
27 |
Correct |
104 ms |
600 KB |
Output is correct |
28 |
Correct |
66 ms |
604 KB |
Output is correct |
29 |
Correct |
150 ms |
604 KB |
Output is correct |
30 |
Correct |
96 ms |
620 KB |
Output is correct |
31 |
Correct |
178 ms |
604 KB |
Output is correct |
32 |
Correct |
126 ms |
600 KB |
Output is correct |
33 |
Execution timed out |
1058 ms |
5560 KB |
Time limit exceeded |
34 |
Execution timed out |
1024 ms |
5484 KB |
Time limit exceeded |
35 |
Correct |
125 ms |
5276 KB |
Output is correct |
36 |
Execution timed out |
1078 ms |
7180 KB |
Time limit exceeded |
37 |
Execution timed out |
1066 ms |
6848 KB |
Time limit exceeded |
38 |
Correct |
173 ms |
7012 KB |
Output is correct |
39 |
Execution timed out |
1071 ms |
8516 KB |
Time limit exceeded |
40 |
Execution timed out |
1065 ms |
8456 KB |
Time limit exceeded |
41 |
Correct |
209 ms |
8276 KB |
Output is correct |
42 |
Execution timed out |
1029 ms |
10384 KB |
Time limit exceeded |
43 |
Execution timed out |
1051 ms |
10440 KB |
Time limit exceeded |
44 |
Correct |
258 ms |
10332 KB |
Output is correct |
45 |
Execution timed out |
1036 ms |
12808 KB |
Time limit exceeded |
46 |
Execution timed out |
1029 ms |
12556 KB |
Time limit exceeded |
47 |
Correct |
341 ms |
12372 KB |
Output is correct |
48 |
Execution timed out |
1048 ms |
15124 KB |
Time limit exceeded |
49 |
Execution timed out |
1063 ms |
14840 KB |
Time limit exceeded |
50 |
Correct |
447 ms |
14840 KB |
Output is correct |
51 |
Execution timed out |
1065 ms |
17380 KB |
Time limit exceeded |
52 |
Execution timed out |
1035 ms |
17164 KB |
Time limit exceeded |
53 |
Correct |
469 ms |
17132 KB |
Output is correct |
54 |
Execution timed out |
1069 ms |
20052 KB |
Time limit exceeded |
55 |
Execution timed out |
1053 ms |
19772 KB |
Time limit exceeded |
56 |
Correct |
644 ms |
19768 KB |
Output is correct |
57 |
Execution timed out |
1056 ms |
22940 KB |
Time limit exceeded |
58 |
Execution timed out |
1022 ms |
22664 KB |
Time limit exceeded |
59 |
Correct |
639 ms |
22608 KB |
Output is correct |
60 |
Execution timed out |
1049 ms |
25776 KB |
Time limit exceeded |
61 |
Execution timed out |
1069 ms |
25792 KB |
Time limit exceeded |
62 |
Correct |
835 ms |
25664 KB |
Output is correct |
63 |
Incorrect |
412 ms |
25640 KB |
Output isn't correct |
64 |
Incorrect |
752 ms |
25684 KB |
Output isn't correct |
65 |
Incorrect |
687 ms |
25792 KB |
Output isn't correct |
66 |
Incorrect |
548 ms |
25676 KB |
Output isn't correct |
67 |
Incorrect |
458 ms |
25660 KB |
Output isn't correct |
68 |
Incorrect |
210 ms |
25824 KB |
Output isn't correct |
69 |
Incorrect |
216 ms |
25684 KB |
Output isn't correct |
70 |
Incorrect |
177 ms |
25768 KB |
Output isn't correct |
71 |
Incorrect |
173 ms |
25772 KB |
Output isn't correct |
72 |
Incorrect |
137 ms |
25908 KB |
Output isn't correct |
73 |
Incorrect |
205 ms |
25844 KB |
Output isn't correct |
74 |
Correct |
377 ms |
26248 KB |
Output is correct |
75 |
Correct |
461 ms |
25752 KB |
Output is correct |
76 |
Correct |
437 ms |
25764 KB |
Output is correct |
77 |
Correct |
445 ms |
25728 KB |
Output is correct |
78 |
Incorrect |
525 ms |
25748 KB |
Output isn't correct |
79 |
Correct |
360 ms |
25936 KB |
Output is correct |
80 |
Correct |
377 ms |
25772 KB |
Output is correct |
81 |
Correct |
420 ms |
25888 KB |
Output is correct |
82 |
Correct |
357 ms |
25756 KB |
Output is correct |
83 |
Correct |
607 ms |
25880 KB |
Output is correct |
84 |
Correct |
438 ms |
26032 KB |
Output is correct |
85 |
Correct |
473 ms |
25732 KB |
Output is correct |
86 |
Correct |
575 ms |
25828 KB |
Output is correct |
87 |
Correct |
487 ms |
25948 KB |
Output is correct |
88 |
Correct |
648 ms |
25724 KB |
Output is correct |
89 |
Correct |
609 ms |
25696 KB |
Output is correct |
90 |
Correct |
576 ms |
26008 KB |
Output is correct |
91 |
Correct |
565 ms |
26008 KB |
Output is correct |
92 |
Correct |
520 ms |
25700 KB |
Output is correct |