Submission #281951

# Submission time Handle Problem Language Result Execution time Memory
281951 2020-08-23T16:12:30 Z Plurm Mecho (IOI09_mecho) C++11
100 / 100
432 ms 6308 KB
#include <bits/stdc++.h>
using namespace std;
char t[1024][1024];
char test[1024][1024];
int dist[1024][1024];
int n, s;
class state{
public:
	int x,y,cw;
	state(int a, int b, int c): x(a), y(b), cw(c) {}
};
void propagateBees(queue<state>& q, int limit){
	while(!q.empty() && q.front().cw < limit){
		state cur = q.front();
		q.pop();
		int x = cur.x;
		int y = cur.y;
		int w = cur.cw+1;
		if(x > 1 && (test[x-1][y] == 'G' && dist[x-1][y] > w) || test[x-1][y] == 'M'){
			dist[x-1][y] = w;
			test[x-1][y] = 'H';
			q.emplace(x-1, y, w);
		}
		if(x < n && (test[x+1][y] == 'G' && dist[x+1][y] > w) || test[x+1][y] == 'M'){
			dist[x+1][y] = w;
			test[x+1][y] = 'H';
			q.emplace(x+1, y, w);
		}
		if(y > 1 && (test[x][y-1] == 'G' && dist[x][y-1] > w) || test[x][y-1] == 'M'){
			dist[x][y-1] = w;
			test[x][y-1] = 'H';
			q.emplace(x, y-1, w);
		}
		if(y < n && (test[x][y+1] == 'G' && dist[x][y+1] > w) || test[x][y+1] == 'M'){
			dist[x][y+1] = w;
			test[x][y+1] = 'H';
			q.emplace(x, y+1, w);
		}
	}
}
void propagateMecho(queue<state>& q, int limit){
	while(!q.empty() && q.front().cw < limit){
		state cur = q.front();
		q.pop();
		int x = cur.x;
		int y = cur.y;
		if(test[x][y] != 'M') continue;
		int w = cur.cw+1;
		if(x > 1 && (test[x-1][y] == 'G' || test[x-1][y] == 'D') && dist[x-1][y] > w){
			dist[x-1][y] = w;
			test[x-1][y] = 'M';
			q.emplace(x-1, y, w);
		}
		if(x < n && (test[x+1][y] == 'G' || test[x+1][y] == 'D') && dist[x+1][y] > w){
			dist[x+1][y] = w;
			test[x+1][y] = 'M';
			q.emplace(x+1, y, w);
		}
		if(y > 1 && (test[x][y-1] == 'G' || test[x][y-1] == 'D') && dist[x][y-1] > w){
			dist[x][y-1] = w;
			test[x][y-1] = 'M';
			q.emplace(x, y-1, w);
		}
		if(y < n && (test[x][y+1] == 'G' || test[x][y+1] == 'D') && dist[x][y+1] > w){
			dist[x][y+1] = w;
			test[x][y+1] = 'M';
			q.emplace(x, y+1, w);
		}
	}
}
bool escapePossible(int days){
	if(days == -1) return true;
	queue<state> q, mq;
	int dx, dy;
	for(int i = 1; i <= n; i++){
		for(int j = 1; j <= n; j++){
			test[i][j] = t[i][j];
			dist[i][j] = 1e9;
			if(t[i][j] == 'H'){
				q.emplace(i,j,0);
				dist[i][j] = 0;
			}else if(t[i][j] == 'D'){
				dx = i;
				dy = j;
			}else if(t[i][j] == 'M'){
				mq.emplace(i,j,0);
				dist[i][j] = 0;
			}
		}
	}
	propagateBees(q, days);
	int lm = 0;
	while(!q.empty() || !mq.empty()){
		lm += s;
		propagateMecho(mq, lm);
		if(test[dx][dy] == 'M') return true;
		days++;
		propagateBees(q, days);
	}
	return false;
}
int main(){
	scanf("%d%d",&n,&s);
	for(int i = 1; i <= n; i++){
		scanf("%s", t[i]+1);
	}
	int lo = -1;
	int hi = n*n;
	int mid;
	while(lo < hi){
		mid = (lo+hi+1)/2;
		if(escapePossible(mid)){
			lo = mid;
		}else{
			hi = mid-1;
		}
	}
	printf("%d\n", lo);
	return 0;
}

Compilation message

mecho.cpp: In function 'void propagateBees(std::queue<state>&, int)':
mecho.cpp:19:12: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   19 |   if(x > 1 && (test[x-1][y] == 'G' && dist[x-1][y] > w) || test[x-1][y] == 'M'){
      |      ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mecho.cpp:24:12: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   24 |   if(x < n && (test[x+1][y] == 'G' && dist[x+1][y] > w) || test[x+1][y] == 'M'){
      |      ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mecho.cpp:29:12: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   29 |   if(y > 1 && (test[x][y-1] == 'G' && dist[x][y-1] > w) || test[x][y-1] == 'M'){
      |      ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mecho.cpp:34:12: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   34 |   if(y < n && (test[x][y+1] == 'G' && dist[x][y+1] > w) || test[x][y+1] == 'M'){
      |      ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mecho.cpp: In function 'int main()':
mecho.cpp:103:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  103 |  scanf("%d%d",&n,&s);
      |  ~~~~~^~~~~~~~~~~~~~
mecho.cpp:105:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  105 |   scanf("%s", t[i]+1);
      |   ~~~~~^~~~~~~~~~~~~~
mecho.cpp: In function 'bool escapePossible(int)':
mecho.cpp:96:17: warning: 'dy' may be used uninitialized in this function [-Wmaybe-uninitialized]
   96 |   if(test[dx][dy] == 'M') return true;
      |      ~~~~~~~~~~~^
mecho.cpp:96:17: warning: 'dx' may be used uninitialized in this function [-Wmaybe-uninitialized]
# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 1 ms 384 KB Output is correct
4 Correct 0 ms 384 KB Output is correct
5 Correct 1 ms 384 KB Output is correct
6 Correct 0 ms 384 KB Output is correct
7 Correct 332 ms 5896 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 1 ms 384 KB Output is correct
10 Correct 1 ms 380 KB Output is correct
11 Correct 1 ms 384 KB Output is correct
12 Correct 1 ms 640 KB Output is correct
13 Correct 1 ms 640 KB Output is correct
14 Correct 2 ms 640 KB Output is correct
15 Correct 1 ms 384 KB Output is correct
16 Correct 1 ms 384 KB Output is correct
17 Correct 1 ms 544 KB Output is correct
18 Correct 1 ms 512 KB Output is correct
19 Correct 1 ms 512 KB Output is correct
20 Correct 1 ms 512 KB Output is correct
21 Correct 1 ms 512 KB Output is correct
22 Correct 1 ms 512 KB Output is correct
23 Correct 1 ms 640 KB Output is correct
24 Correct 1 ms 640 KB Output is correct
25 Correct 1 ms 640 KB Output is correct
26 Correct 1 ms 640 KB Output is correct
27 Correct 2 ms 672 KB Output is correct
28 Correct 1 ms 768 KB Output is correct
29 Correct 1 ms 768 KB Output is correct
30 Correct 1 ms 768 KB Output is correct
31 Correct 1 ms 768 KB Output is correct
32 Correct 1 ms 768 KB Output is correct
33 Correct 25 ms 2680 KB Output is correct
34 Correct 24 ms 2560 KB Output is correct
35 Correct 46 ms 2560 KB Output is correct
36 Correct 31 ms 2944 KB Output is correct
37 Correct 33 ms 2944 KB Output is correct
38 Correct 59 ms 2944 KB Output is correct
39 Correct 40 ms 3200 KB Output is correct
40 Correct 41 ms 3200 KB Output is correct
41 Correct 79 ms 3200 KB Output is correct
42 Correct 50 ms 3584 KB Output is correct
43 Correct 51 ms 3712 KB Output is correct
44 Correct 100 ms 3584 KB Output is correct
45 Correct 64 ms 3968 KB Output is correct
46 Correct 63 ms 3968 KB Output is correct
47 Correct 124 ms 3968 KB Output is correct
48 Correct 73 ms 4332 KB Output is correct
49 Correct 78 ms 4344 KB Output is correct
50 Correct 157 ms 4344 KB Output is correct
51 Correct 90 ms 4608 KB Output is correct
52 Correct 89 ms 4608 KB Output is correct
53 Correct 184 ms 4608 KB Output is correct
54 Correct 104 ms 4992 KB Output is correct
55 Correct 106 ms 5064 KB Output is correct
56 Correct 220 ms 5112 KB Output is correct
57 Correct 125 ms 5528 KB Output is correct
58 Correct 125 ms 5376 KB Output is correct
59 Correct 237 ms 5376 KB Output is correct
60 Correct 140 ms 5632 KB Output is correct
61 Correct 134 ms 5632 KB Output is correct
62 Correct 272 ms 5632 KB Output is correct
63 Correct 319 ms 5632 KB Output is correct
64 Correct 307 ms 5736 KB Output is correct
65 Correct 316 ms 5632 KB Output is correct
66 Correct 313 ms 5632 KB Output is correct
67 Correct 329 ms 5736 KB Output is correct
68 Correct 312 ms 5760 KB Output is correct
69 Correct 289 ms 5760 KB Output is correct
70 Correct 309 ms 5776 KB Output is correct
71 Correct 321 ms 5884 KB Output is correct
72 Correct 302 ms 5760 KB Output is correct
73 Correct 342 ms 6152 KB Output is correct
74 Correct 364 ms 6144 KB Output is correct
75 Correct 432 ms 6144 KB Output is correct
76 Correct 368 ms 6144 KB Output is correct
77 Correct 388 ms 6308 KB Output is correct
78 Correct 400 ms 6256 KB Output is correct
79 Correct 378 ms 6156 KB Output is correct
80 Correct 349 ms 6104 KB Output is correct
81 Correct 338 ms 6228 KB Output is correct
82 Correct 337 ms 6108 KB Output is correct
83 Correct 375 ms 6116 KB Output is correct
84 Correct 342 ms 6032 KB Output is correct
85 Correct 356 ms 6180 KB Output is correct
86 Correct 347 ms 6036 KB Output is correct
87 Correct 334 ms 6276 KB Output is correct
88 Correct 341 ms 5860 KB Output is correct
89 Correct 348 ms 6000 KB Output is correct
90 Correct 339 ms 5836 KB Output is correct
91 Correct 344 ms 5896 KB Output is correct
92 Correct 353 ms 5876 KB Output is correct