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Submission #335744

# Submission time Handle Problem Language Result Execution time Memory
335744 2020-12-13T19:58:58 Z DavidDamian Mecho (IOI09_mecho) C++11
100 / 100
 253 ms 8940 KB 
#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 150 ms 8684 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 896 KB Output is correct
14 Correct 1 ms 1004 KB Output is correct
15 Correct 1 ms 492 KB Output is correct
16 Correct 1 ms 492 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 620 KB Output is correct
21 Correct 1 ms 748 KB Output is correct
22 Correct 1 ms 896 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 1004 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 2 ms 1132 KB Output is correct
32 Correct 1 ms 1132 KB Output is correct
33 Correct 14 ms 3948 KB Output is correct
34 Correct 12 ms 4076 KB Output is correct
35 Correct 31 ms 3948 KB Output is correct
36 Correct 21 ms 4460 KB Output is correct
37 Correct 18 ms 4460 KB Output is correct
38 Correct 54 ms 4460 KB Output is correct
39 Correct 31 ms 4972 KB Output is correct
40 Correct 26 ms 4972 KB Output is correct
41 Correct 60 ms 4972 KB Output is correct
42 Correct 49 ms 5484 KB Output is correct
43 Correct 35 ms 5484 KB Output is correct
44 Correct 70 ms 5612 KB Output is correct
45 Correct 56 ms 5996 KB Output is correct
46 Correct 47 ms 5996 KB Output is correct
47 Correct 95 ms 5996 KB Output is correct
48 Correct 86 ms 6508 KB Output is correct
49 Correct 62 ms 6508 KB Output is correct
50 Correct 100 ms 6656 KB Output is correct
51 Correct 98 ms 7148 KB Output is correct
52 Correct 83 ms 7020 KB Output is correct
53 Correct 129 ms 7020 KB Output is correct
54 Correct 130 ms 7532 KB Output is correct
55 Correct 104 ms 7532 KB Output is correct
56 Correct 150 ms 7544 KB Output is correct
57 Correct 165 ms 8044 KB Output is correct
58 Correct 136 ms 8044 KB Output is correct
59 Correct 171 ms 8044 KB Output is correct
60 Correct 206 ms 8556 KB Output is correct
61 Correct 168 ms 8604 KB Output is correct
62 Correct 217 ms 8556 KB Output is correct
63 Correct 139 ms 8556 KB Output is correct
64 Correct 253 ms 8556 KB Output is correct
65 Correct 219 ms 8608 KB Output is correct
66 Correct 191 ms 8608 KB Output is correct
67 Correct 142 ms 8556 KB Output is correct
68 Correct 71 ms 8556 KB Output is correct
69 Correct 61 ms 8520 KB Output is correct
70 Correct 58 ms 8512 KB Output is correct
71 Correct 64 ms 8556 KB Output is correct
72 Correct 51 ms 8556 KB Output is correct
73 Correct 50 ms 8812 KB Output is correct
74 Correct 95 ms 8940 KB Output is correct
75 Correct 108 ms 8940 KB Output is correct
76 Correct 125 ms 8940 KB Output is correct
77 Correct 108 ms 8812 KB Output is correct
78 Correct 111 ms 8940 KB Output is correct
79 Correct 80 ms 8812 KB Output is correct
80 Correct 94 ms 8764 KB Output is correct
81 Correct 109 ms 8812 KB Output is correct
82 Correct 100 ms 8812 KB Output is correct
83 Correct 150 ms 8812 KB Output is correct
84 Correct 120 ms 8940 KB Output is correct
85 Correct 117 ms 8812 KB Output is correct
86 Correct 125 ms 8812 KB Output is correct
87 Correct 134 ms 8940 KB Output is correct
88 Correct 119 ms 8684 KB Output is correct
89 Correct 128 ms 8684 KB Output is correct
90 Correct 139 ms 8684 KB Output is correct
91 Correct 147 ms 8812 KB Output is correct
92 Correct 140 ms 8812 KB Output is correct