Submission #138813

# Submission time Handle Problem Language Result Execution time Memory
138813 2019-07-30T11:08:07 Z Boxworld Mecho (IOI09_mecho) C++14
100 / 100
247 ms 9976 KB
#include <bits/stdc++.h>
using namespace std;
const int N=1010;
typedef pair<int,int> pii;
char G[N][N];
int dx[4]={1,-1,0,0},dy[4]={0,0,1,-1};
int T[N][N],d[N][N],vis[N][N];
int n,s,sx,sy;
int bfs(int time){
	if (time*s>=T[sx][sy])return 0;
	memset(vis,0,sizeof(vis));
	queue<pii> Q;
	vis[sx][sy]=1;
	Q.push(make_pair(sx*N+sy,time*s));
	while(!Q.empty()){
		int dis=Q.front().second;
		int x=Q.front().first/N;
		int y=Q.front().first%N;
		Q.pop();
		if (G[x][y]=='D')return 1;
		for (int k=0;k<4;k++){
			int X=x+dx[k],Y=y+dy[k];
			if (X<1||X>n||Y<1||Y>n||G[X][Y]=='T'||dis+1>=T[X][Y]||vis[X][Y])continue;
			vis[X][Y]=1;
			Q.push(make_pair(X*N+Y,dis+1));
		}
	}
	return 0;
}
int main(){
	scanf("%d%d",&n,&s);
	for (int i=1;i<=n;i++)scanf("%s",G[i]+1);
	memset(T,-1,sizeof(T));
	queue<int> bq;
	for (int i=1;i<=n;i++)
	for (int j=1;j<=n;j++){
		if (G[i][j]=='M')sx=i,sy=j;
		if (G[i][j]=='D')T[i][j]=n*n*s;
		if (G[i][j]=='H'){
			T[i][j]=0;
			bq.push(i*N+j);
		}
	}
	while(!bq.empty()){
		int x=bq.front()/N,y=bq.front()%N;
		bq.pop();
		for (int i=0;i<4;i++){
			int X=x+dx[i],Y=y+dy[i];
			if (x<1||x>n||y<1||y>n||T[X][Y]!=-1)continue;
			if (G[X][Y]=='T'||G[X][Y]=='D')continue;
			T[X][Y]=T[x][y]+s;
			bq.push(X*N+Y);
		}
	}
	int l=-1,r=n*n*2;
	while(l+1<r){
		int m=(l+r)/2;
		if (bfs(m))l=m;
		else r=m;
	}
	printf("%d\n",l);
}

Compilation message

mecho.cpp: In function 'int main()':
mecho.cpp:31:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n,&s);
  ~~~~~^~~~~~~~~~~~~~
mecho.cpp:32:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for (int i=1;i<=n;i++)scanf("%s",G[i]+1);
                        ~~~~~^~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 9 ms 8312 KB Output is correct
2 Correct 9 ms 8312 KB Output is correct
3 Correct 9 ms 8440 KB Output is correct
4 Correct 9 ms 8316 KB Output is correct
5 Correct 8 ms 8312 KB Output is correct
6 Correct 9 ms 8360 KB Output is correct
7 Correct 120 ms 9796 KB Output is correct
8 Correct 11 ms 8312 KB Output is correct
9 Correct 11 ms 8312 KB Output is correct
10 Correct 12 ms 8312 KB Output is correct
11 Correct 11 ms 8312 KB Output is correct
12 Correct 22 ms 8412 KB Output is correct
13 Correct 11 ms 8440 KB Output is correct
14 Correct 10 ms 8312 KB Output is correct
15 Correct 12 ms 8312 KB Output is correct
16 Correct 11 ms 8284 KB Output is correct
17 Correct 12 ms 8312 KB Output is correct
18 Correct 10 ms 8312 KB Output is correct
19 Correct 10 ms 8312 KB Output is correct
20 Correct 11 ms 8312 KB Output is correct
21 Correct 12 ms 8312 KB Output is correct
22 Correct 13 ms 8440 KB Output is correct
23 Correct 10 ms 8312 KB Output is correct
24 Correct 10 ms 8296 KB Output is correct
25 Correct 10 ms 8312 KB Output is correct
26 Correct 11 ms 8440 KB Output is correct
27 Correct 10 ms 8312 KB Output is correct
28 Correct 11 ms 8440 KB Output is correct
29 Correct 11 ms 8440 KB Output is correct
30 Correct 10 ms 8312 KB Output is correct
31 Correct 11 ms 8436 KB Output is correct
32 Correct 13 ms 8440 KB Output is correct
33 Correct 13 ms 8696 KB Output is correct
34 Correct 14 ms 8824 KB Output is correct
35 Correct 32 ms 8796 KB Output is correct
36 Correct 14 ms 8948 KB Output is correct
37 Correct 15 ms 8952 KB Output is correct
38 Correct 50 ms 8952 KB Output is correct
39 Correct 15 ms 8956 KB Output is correct
40 Correct 15 ms 8952 KB Output is correct
41 Correct 51 ms 9008 KB Output is correct
42 Correct 16 ms 9080 KB Output is correct
43 Correct 18 ms 9208 KB Output is correct
44 Correct 62 ms 9104 KB Output is correct
45 Correct 17 ms 9080 KB Output is correct
46 Correct 17 ms 9080 KB Output is correct
47 Correct 69 ms 9200 KB Output is correct
48 Correct 18 ms 9336 KB Output is correct
49 Correct 18 ms 9208 KB Output is correct
50 Correct 89 ms 9336 KB Output is correct
51 Correct 19 ms 9336 KB Output is correct
52 Correct 19 ms 9336 KB Output is correct
53 Correct 108 ms 9336 KB Output is correct
54 Correct 21 ms 9464 KB Output is correct
55 Correct 20 ms 9464 KB Output is correct
56 Correct 124 ms 9592 KB Output is correct
57 Correct 22 ms 9592 KB Output is correct
58 Correct 23 ms 9592 KB Output is correct
59 Correct 149 ms 9740 KB Output is correct
60 Correct 23 ms 9720 KB Output is correct
61 Correct 23 ms 9720 KB Output is correct
62 Correct 167 ms 9848 KB Output is correct
63 Correct 125 ms 9720 KB Output is correct
64 Correct 247 ms 9852 KB Output is correct
65 Correct 184 ms 9720 KB Output is correct
66 Correct 148 ms 9812 KB Output is correct
67 Correct 140 ms 9720 KB Output is correct
68 Correct 57 ms 9848 KB Output is correct
69 Correct 58 ms 9720 KB Output is correct
70 Correct 43 ms 9720 KB Output is correct
71 Correct 49 ms 9720 KB Output is correct
72 Correct 37 ms 9764 KB Output is correct
73 Correct 40 ms 9848 KB Output is correct
74 Correct 69 ms 9976 KB Output is correct
75 Correct 86 ms 9848 KB Output is correct
76 Correct 76 ms 9904 KB Output is correct
77 Correct 75 ms 9864 KB Output is correct
78 Correct 96 ms 9848 KB Output is correct
79 Correct 58 ms 9820 KB Output is correct
80 Correct 76 ms 9976 KB Output is correct
81 Correct 85 ms 9848 KB Output is correct
82 Correct 73 ms 9820 KB Output is correct
83 Correct 99 ms 9848 KB Output is correct
84 Correct 89 ms 9848 KB Output is correct
85 Correct 101 ms 9852 KB Output is correct
86 Correct 98 ms 9848 KB Output is correct
87 Correct 97 ms 9912 KB Output is correct
88 Correct 108 ms 9896 KB Output is correct
89 Correct 111 ms 9848 KB Output is correct
90 Correct 108 ms 9848 KB Output is correct
91 Correct 106 ms 9848 KB Output is correct
92 Correct 114 ms 9948 KB Output is correct