| # |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
| 621486 |
2022-08-03T21:09:42 Z |
abcisosm5 |
Mecho (IOI09_mecho) |
C++17 |
|
310 ms |
2036 KB |
#include <bits/stdc++.h>
using namespace std;
#define pi pair<int, int>
#define f first
#define s second
int N, S;
const int MN = 800;
char grid[MN][MN] = {{}};
vector<pi> hives;
pi M; pi D;
int dx[4] = {1, -1, 0, 0};
int dy[4] = {0, 0, 1, -1};
void movebees(queue<pair<pi,int>> (&b), char (&v)[MN][MN], int t){
if(b.empty()) return;
int start = b.front().s;
for(int i = 0; i < t; i++){
while(!b.empty() && b.front().s <= start + i){
pair<pi, int> x = b.front(); b.pop();
pi p = x.f; int index = x.s;
for(int d = 0; d < 4; d++){
int nx = p.f + dx[d]; int ny = p.s + dy[d];
if(nx < 0 || nx >= N || ny < 0 || ny >= N) continue;
if(v[nx][ny] != 'B' && (grid[nx][ny] == 'G' || grid[nx][ny] == 'M')){
v[nx][ny] = 'B';
b.push({{nx, ny}, index+1});
}
}
}
}
}
bool movemecho(queue<pair<pi, int>> (&m), char (&v)[MN][MN]){
if(m.empty()) return false;
int start = m.front().s;
for(int i = 0; i < S; i++){
while(!m.empty() && m.front().s <= start + i){
pair<pi, int> x = m.front(); m.pop();
pi p = x.f; int index = x.s;
if(v[p.f][p.s] == 'B') continue; //invalidate positions that are now occupied by bees
for(int d = 0; d < 4; d++){
int nx = p.f + dx[d]; int ny = p.s + dy[d];
if(nx < 0 || nx >= N || ny < 0 || ny >= N) continue;
if(!v[nx][ny] && grid[nx][ny] != 'T'){
v[nx][ny] = 'M';
if(grid[nx][ny] == 'D') return true;
m.push({{nx, ny}, index+1});
}
}
}
}
return false;
}
bool works(int t){ //O(N^2)
char visited[MN][MN] = {{}};
queue<pair<pi, int>> mecho; mecho.push({M,0}); visited[M.f][M.s] = 'M';
queue<pair<pi, int>> bees;
for(pi p : hives){
bees.push({p,0});
visited[p.first][p.second] = 'B';
}
movebees(bees, visited, t);
for(int i = 0; i < N*N/2; i++){
//first, move mecho S steps
if(mecho.empty()) break;
bool success = movemecho(mecho, visited);
if(success) return true;
//then, move bees 1 step
movebees(bees, visited, 1);
}
return false;
}
int main(){
cin.tie(0)->sync_with_stdio(0);
cin >> N >> S;
for(int i = 0; i < N; i++){
for(int j = 0; j < N; j++){
cin >> grid[i][j];
if(grid[i][j] == 'M') M = {i, j};
if(grid[i][j] == 'D') D = {i, j};
if(grid[i][j] == 'H') hives.push_back({i,j});
}
}
int lo = -1; int hi = N*N/2; //amount of head start to bees
while(lo < hi){ // in total, O(N^2 log N)
int mid = lo + (hi - lo + 1) / 2;
if(works(mid)){
lo = mid;
} else {
hi = mid - 1;
}
}
cout << lo;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
852 KB |
Output is correct |
| 2 |
Correct |
1 ms |
852 KB |
Output is correct |
| 3 |
Correct |
1 ms |
852 KB |
Output is correct |
| 4 |
Correct |
1 ms |
852 KB |
Output is correct |
| 5 |
Correct |
1 ms |
852 KB |
Output is correct |
| 6 |
Correct |
1 ms |
852 KB |
Output is correct |
| 7 |
Correct |
236 ms |
1724 KB |
Output is correct |
| 8 |
Correct |
1 ms |
852 KB |
Output is correct |
| 9 |
Correct |
1 ms |
852 KB |
Output is correct |
| 10 |
Correct |
2 ms |
852 KB |
Output is correct |
| 11 |
Correct |
1 ms |
852 KB |
Output is correct |
| 12 |
Correct |
1 ms |
980 KB |
Output is correct |
| 13 |
Correct |
2 ms |
1000 KB |
Output is correct |
| 14 |
Correct |
2 ms |
980 KB |
Output is correct |
| 15 |
Correct |
1 ms |
852 KB |
Output is correct |
| 16 |
Correct |
1 ms |
852 KB |
Output is correct |
| 17 |
Correct |
1 ms |
852 KB |
Output is correct |
| 18 |
Correct |
1 ms |
852 KB |
Output is correct |
| 19 |
Correct |
1 ms |
852 KB |
Output is correct |
| 20 |
Correct |
1 ms |
852 KB |
Output is correct |
| 21 |
Correct |
1 ms |
852 KB |
Output is correct |
| 22 |
Correct |
1 ms |
980 KB |
Output is correct |
| 23 |
Correct |
1 ms |
980 KB |
Output is correct |
| 24 |
Correct |
1 ms |
980 KB |
Output is correct |
| 25 |
Correct |
1 ms |
980 KB |
Output is correct |
| 26 |
Correct |
2 ms |
980 KB |
Output is correct |
| 27 |
Correct |
1 ms |
980 KB |
Output is correct |
| 28 |
Correct |
1 ms |
980 KB |
Output is correct |
| 29 |
Correct |
2 ms |
980 KB |
Output is correct |
| 30 |
Correct |
2 ms |
980 KB |
Output is correct |
| 31 |
Correct |
2 ms |
992 KB |
Output is correct |
| 32 |
Correct |
3 ms |
980 KB |
Output is correct |
| 33 |
Correct |
22 ms |
1220 KB |
Output is correct |
| 34 |
Correct |
19 ms |
1108 KB |
Output is correct |
| 35 |
Correct |
33 ms |
1108 KB |
Output is correct |
| 36 |
Correct |
27 ms |
1252 KB |
Output is correct |
| 37 |
Correct |
30 ms |
1268 KB |
Output is correct |
| 38 |
Correct |
46 ms |
1236 KB |
Output is correct |
| 39 |
Correct |
38 ms |
1236 KB |
Output is correct |
| 40 |
Correct |
34 ms |
1284 KB |
Output is correct |
| 41 |
Correct |
59 ms |
1236 KB |
Output is correct |
| 42 |
Correct |
46 ms |
1328 KB |
Output is correct |
| 43 |
Correct |
46 ms |
1316 KB |
Output is correct |
| 44 |
Correct |
78 ms |
1324 KB |
Output is correct |
| 45 |
Correct |
65 ms |
1360 KB |
Output is correct |
| 46 |
Correct |
70 ms |
1376 KB |
Output is correct |
| 47 |
Correct |
99 ms |
1384 KB |
Output is correct |
| 48 |
Correct |
76 ms |
1396 KB |
Output is correct |
| 49 |
Correct |
72 ms |
1396 KB |
Output is correct |
| 50 |
Correct |
106 ms |
1408 KB |
Output is correct |
| 51 |
Correct |
85 ms |
1436 KB |
Output is correct |
| 52 |
Correct |
81 ms |
1428 KB |
Output is correct |
| 53 |
Correct |
139 ms |
1452 KB |
Output is correct |
| 54 |
Correct |
116 ms |
1492 KB |
Output is correct |
| 55 |
Correct |
87 ms |
1492 KB |
Output is correct |
| 56 |
Correct |
183 ms |
1504 KB |
Output is correct |
| 57 |
Correct |
105 ms |
1516 KB |
Output is correct |
| 58 |
Correct |
99 ms |
1492 KB |
Output is correct |
| 59 |
Correct |
143 ms |
1540 KB |
Output is correct |
| 60 |
Correct |
118 ms |
1488 KB |
Output is correct |
| 61 |
Correct |
109 ms |
1612 KB |
Output is correct |
| 62 |
Correct |
166 ms |
1580 KB |
Output is correct |
| 63 |
Correct |
239 ms |
1556 KB |
Output is correct |
| 64 |
Correct |
269 ms |
1580 KB |
Output is correct |
| 65 |
Correct |
244 ms |
1560 KB |
Output is correct |
| 66 |
Correct |
269 ms |
1564 KB |
Output is correct |
| 67 |
Correct |
248 ms |
1564 KB |
Output is correct |
| 68 |
Correct |
255 ms |
1596 KB |
Output is correct |
| 69 |
Correct |
225 ms |
1612 KB |
Output is correct |
| 70 |
Correct |
249 ms |
1620 KB |
Output is correct |
| 71 |
Correct |
272 ms |
1620 KB |
Output is correct |
| 72 |
Correct |
303 ms |
1604 KB |
Output is correct |
| 73 |
Correct |
196 ms |
2016 KB |
Output is correct |
| 74 |
Correct |
253 ms |
2004 KB |
Output is correct |
| 75 |
Correct |
289 ms |
2004 KB |
Output is correct |
| 76 |
Correct |
306 ms |
2004 KB |
Output is correct |
| 77 |
Correct |
257 ms |
2004 KB |
Output is correct |
| 78 |
Correct |
259 ms |
1948 KB |
Output is correct |
| 79 |
Correct |
266 ms |
1948 KB |
Output is correct |
| 80 |
Correct |
263 ms |
1948 KB |
Output is correct |
| 81 |
Correct |
263 ms |
1944 KB |
Output is correct |
| 82 |
Correct |
271 ms |
1960 KB |
Output is correct |
| 83 |
Correct |
269 ms |
1888 KB |
Output is correct |
| 84 |
Correct |
294 ms |
1888 KB |
Output is correct |
| 85 |
Correct |
284 ms |
1908 KB |
Output is correct |
| 86 |
Correct |
270 ms |
2036 KB |
Output is correct |
| 87 |
Correct |
310 ms |
1880 KB |
Output is correct |
| 88 |
Correct |
256 ms |
1804 KB |
Output is correct |
| 89 |
Correct |
262 ms |
1804 KB |
Output is correct |
| 90 |
Correct |
256 ms |
1808 KB |
Output is correct |
| 91 |
Correct |
257 ms |
1816 KB |
Output is correct |
| 92 |
Correct |
261 ms |
1812 KB |
Output is correct |
