Submission #335753

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
335753	2020-12-13T20:33:35 Z	Christopher_Rdz	Mecho (IOI09_mecho)	C++14	100 / 100	256 ms	9196 KB

mecho

#include <bits/stdc++.h>
using namespace std;
struct node{
    int i;
    int j;
    node(){}
    node(int I,int J){
        i=I;
        j=J;
    }
};
queue<node> Q;
char forest[805][805];
int bees[805][805];
int dist[805][805];
int energy[805][805];
int dx[4]={1,-1,0,0};
int dy[4]={0,0,1,-1};
int n,s;

void bfsBees(){    for (int i = 1; i <= n; i++){        for (int j = 1; j <= n; j++){            bees[i][j]=INT_MAX;
            if(forest[i][j]=='H'){
                Q.push(node(i,j));
                bees[i][j]=0;            }       }    }
    while(!Q.empty()){
        node u=Q.front();
        Q.pop();
        for(int mov=0;mov<4;mov++){
            int i=u.i+dx[mov];
            int j=u.j+dy[mov];
            if(i<1 || i>n) continue;
            if(j<1 || j>n) continue;
            if(forest[i][j]=='T' || forest[i][j]=='D') continue;
            if(bees[i][j]==INT_MAX){
                bees[i][j]=bees[u.i][u.j]+1;
                Q.push(node(i,j));
            }
        }
    }
}

node mecho;
node home;

bool bfsMecho(int init){    for (int i = 1; i <= n; i++){        for (int j = 1; j <= n; j++){            dist[i][j]=INT_MAX;
            energy[i][j]=0;        }}
    if(bees[mecho.i][mecho.j]<=init) return false;
    dist[mecho.i][mecho.j]=init;
    energy[mecho.i][mecho.j]=0;
    Q.push(mecho);
    while(!Q.empty()){
        node u=Q.front();
        Q.pop();
        if(bees[u.i][u.j]==dist[u.i][u.j] && energy[u.i][u.j]==0) continue;
        for(int mov=0;mov<4;mov++){
            int i=u.i+dx[mov];
            int j=u.j+dy[mov];
            if(i<1 || i>n) continue;
            if(j<1 || j>n) continue;
            if(forest[i][j]=='T') continue;
            if(dist[i][j]==INT_MAX){
                int change=(energy[u.i][u.j]>0)? 0 : 1;
                dist[i][j]=dist[u.i][u.j]+change;
                if(bees[i][j]<dist[i][j]) continue;
                energy[i][j]=(energy[u.i][u.j]>0)? energy[u.i][u.j]-1 : s-1;
                Q.push(node(i,j));
            }
        }
    }
    return dist[home.i][home.j]!=INT_MAX;
}

int binarySearch(){
    int k=-1;
    int L=0,R=3*n;
    while(L<R){
        int mid=(L+R)/2;
        if(bfsMecho(mid)){
            k=mid;
            L=mid+1;
        }
        else{
            R=mid;
        }
    }
    return k;
}

int binarySearch2(){
    int k=-1;
    for(int b=5000;b>=1;b/=2){
        while(bfsMecho(b+k)) k+=b;
    }
    return k;
}

int main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);
    cin>>n>>s;
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            cin>>forest[i][j];
            if(forest[i][j]=='M'){
                mecho=node(i,j);
            }
            else if(forest[i][j]=='D'){
                home=node(i,j);
            }
        }
    }        
    bfsBees();
    int ans=binarySearch2();
    cout<<ans<<endl;
    return 0;
}

Subtask #1

100.0 / 100.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	364 KB	Output is correct
2	Correct	1 ms	364 KB	Output is correct
3	Correct	1 ms	364 KB	Output is correct
4	Correct	1 ms	364 KB	Output is correct
5	Correct	1 ms	492 KB	Output is correct
6	Correct	1 ms	492 KB	Output is correct
7	Correct	151 ms	8940 KB	Output is correct
8	Correct	1 ms	492 KB	Output is correct
9	Correct	1 ms	492 KB	Output is correct
10	Correct	1 ms	492 KB	Output is correct
11	Correct	1 ms	492 KB	Output is correct
12	Correct	1 ms	1004 KB	Output is correct
13	Correct	1 ms	876 KB	Output is correct
14	Correct	1 ms	1004 KB	Output is correct
15	Correct	1 ms	620 KB	Output is correct
16	Correct	1 ms	620 KB	Output is correct
17	Correct	1 ms	620 KB	Output is correct
18	Correct	1 ms	620 KB	Output is correct
19	Correct	1 ms	620 KB	Output is correct
20	Correct	1 ms	640 KB	Output is correct
21	Correct	1 ms	748 KB	Output is correct
22	Correct	1 ms	748 KB	Output is correct
23	Correct	1 ms	876 KB	Output is correct
24	Correct	1 ms	876 KB	Output is correct
25	Correct	1 ms	1004 KB	Output is correct
26	Correct	1 ms	1004 KB	Output is correct
27	Correct	1 ms	1024 KB	Output is correct
28	Correct	1 ms	1004 KB	Output is correct
29	Correct	1 ms	1132 KB	Output is correct
30	Correct	1 ms	1132 KB	Output is correct
31	Correct	1 ms	1132 KB	Output is correct
32	Correct	1 ms	1152 KB	Output is correct
33	Correct	14 ms	4088 KB	Output is correct
34	Correct	12 ms	4076 KB	Output is correct
35	Correct	32 ms	4076 KB	Output is correct
36	Correct	22 ms	4716 KB	Output is correct
37	Correct	18 ms	4716 KB	Output is correct
38	Correct	42 ms	4588 KB	Output is correct
39	Correct	30 ms	5228 KB	Output is correct
40	Correct	26 ms	5100 KB	Output is correct
41	Correct	56 ms	5228 KB	Output is correct
42	Correct	42 ms	5612 KB	Output is correct
43	Correct	37 ms	5612 KB	Output is correct
44	Correct	69 ms	5740 KB	Output is correct
45	Correct	58 ms	6272 KB	Output is correct
46	Correct	54 ms	6252 KB	Output is correct
47	Correct	85 ms	6252 KB	Output is correct
48	Correct	77 ms	6764 KB	Output is correct
49	Correct	67 ms	6636 KB	Output is correct
50	Correct	104 ms	6892 KB	Output is correct
51	Correct	101 ms	7276 KB	Output is correct
52	Correct	82 ms	7148 KB	Output is correct
53	Correct	129 ms	7280 KB	Output is correct
54	Correct	127 ms	7660 KB	Output is correct
55	Correct	103 ms	7660 KB	Output is correct
56	Correct	146 ms	7788 KB	Output is correct
57	Correct	164 ms	8300 KB	Output is correct
58	Correct	133 ms	8172 KB	Output is correct
59	Correct	170 ms	8172 KB	Output is correct
60	Correct	205 ms	8684 KB	Output is correct
61	Correct	168 ms	8684 KB	Output is correct
62	Correct	194 ms	8812 KB	Output is correct
63	Correct	136 ms	8684 KB	Output is correct
64	Correct	256 ms	8904 KB	Output is correct
65	Correct	219 ms	8684 KB	Output is correct
66	Correct	187 ms	8684 KB	Output is correct
67	Correct	143 ms	8804 KB	Output is correct
68	Correct	70 ms	8812 KB	Output is correct
69	Correct	61 ms	8832 KB	Output is correct
70	Correct	59 ms	8832 KB	Output is correct
71	Correct	55 ms	8812 KB	Output is correct
72	Correct	51 ms	8812 KB	Output is correct
73	Correct	50 ms	9068 KB	Output is correct
74	Correct	93 ms	9068 KB	Output is correct
75	Correct	109 ms	9196 KB	Output is correct
76	Correct	105 ms	9068 KB	Output is correct
77	Correct	87 ms	9196 KB	Output is correct
78	Correct	101 ms	9068 KB	Output is correct
79	Correct	78 ms	8940 KB	Output is correct
80	Correct	95 ms	8940 KB	Output is correct
81	Correct	114 ms	9056 KB	Output is correct
82	Correct	97 ms	8940 KB	Output is correct
83	Correct	112 ms	8940 KB	Output is correct
84	Correct	121 ms	8940 KB	Output is correct
85	Correct	117 ms	9068 KB	Output is correct
86	Correct	127 ms	8940 KB	Output is correct
87	Correct	130 ms	8940 KB	Output is correct
88	Correct	115 ms	8940 KB	Output is correct
89	Correct	124 ms	9196 KB	Output is correct
90	Correct	142 ms	9068 KB	Output is correct
91	Correct	149 ms	9068 KB	Output is correct
92	Correct	134 ms	8940 KB	Output is correct