oj.uz

Submission #411435

# Submission time Handle Problem Language Result Execution time Memory
411435 2021-05-25T10:12:55 Z pliam Mecho (IOI09_mecho) C++14
100 / 100
 299 ms 8136 KB 
#include <bits/stdc++.h>
using namespace std;
#define MAXN 805
#define INF (int)1e9
typedef pair<int,int> pii;

int N,S;
char grid[MAXN][MAXN];
int dist_bees[MAXN][MAXN];
int dist_mecho[MAXN][MAXN];
pii mecho,home;

const vector<pii> deltas={{1,0},{-1,0},{0,1},{0,-1}};

bool inbounds(int x,int y){
    return 1<=x&&x<=N&&1<=y&&y<=N;
}

bool check(int k){//k<=dist_bees[mecho.first][mecho.second]-1
    queue<pii> q;
    bool used[MAXN][MAXN];
    for(int i=1;i<=N;i++){
        for(int j=1;j<=N;j++){
            used[i][j]=false;
            dist_mecho[i][j]=INF;
        }
    }
    used[mecho.first][mecho.second]=true;
    dist_mecho[mecho.first][mecho.second]=0;
    q.push(mecho);
    while(!q.empty()){
        pii p=q.front();
        q.pop();
        int x=p.first;
        int y=p.second;
        for(auto d:deltas){
            int x_=x+d.first;
            int y_=y+d.second;
            int steps=dist_mecho[x][y]+1;
            if(make_pair(x_,y_)==home) return true;
            if(inbounds(x_,y_)&&grid[x_][y_]=='G'&&!used[x_][y_]&&(steps/S+k<dist_bees[x_][y_])){
                used[x_][y_]=true;
                dist_mecho[x_][y_]=steps;
                q.push({x_,y_});
            }
        }
    }
    return false;
}

int main(){
    scanf("%d%d",&N,&S);
    queue<pii> q;
    bool used[MAXN][MAXN];
    for(int i=1;i<=N;i++){
        for(int j=1;j<=N;j++){
            used[i][j]=false;
            dist_bees[i][j]=INF;
            scanf(" %c",&grid[i][j]);
            if(grid[i][j]=='M') mecho={i,j};
            else if(grid[i][j]=='D') home={i,j};
            else if(grid[i][j]=='H'){
                q.push({i,j});//hive
                dist_bees[i][j]=0;
                used[i][j]=true;
            }
        }
    }
    while(!q.empty()){
        pii p=q.front();
        q.pop();
        int x=p.first;
        int y=p.second;
        for(auto d:deltas){
            int x_=x+d.first;
            int y_=y+d.second;
            if(inbounds(x_,y_)&&(grid[x_][y_]=='G'||grid[x_][y_]=='M')&&!used[x_][y_]){
                used[x_][y_]=true;
                dist_bees[x_][y_]=dist_bees[x][y]+1;
                q.push({x_,y_});
            }
        }
    }
    int ans=0;
    int max_ans=dist_bees[mecho.first][mecho.second]-1;
    for(int b=max_ans;b>0;b/=2){
        while(ans+b<=max_ans&&check(ans+b)) ans+=b;
    }
    printf("%d\n",check(ans)?ans:-1);
}

Compilation message

mecho.cpp: In function 'int main()':
mecho.cpp:52:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   52 |     scanf("%d%d",&N,&S);
      |     ~~~~~^~~~~~~~~~~~~~
mecho.cpp:59:18: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   59 |             scanf(" %c",&grid[i][j]);
      |             ~~~~~^~~~~~~~~~~~~~~~~~~

Subtask #1
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1484 KB Output is correct
2 Correct 1 ms 1612 KB Output is correct
3 Correct 1 ms 1612 KB Output is correct
4 Correct 1 ms 1612 KB Output is correct
5 Correct 1 ms 1612 KB Output is correct
6 Correct 1 ms 1572 KB Output is correct
7 Correct 159 ms 7964 KB Output is correct
8 Correct 1 ms 1612 KB Output is correct
9 Correct 1 ms 1612 KB Output is correct
10 Correct 1 ms 1612 KB Output is correct
11 Correct 1 ms 1612 KB Output is correct
12 Correct 2 ms 1996 KB Output is correct
13 Correct 2 ms 1868 KB Output is correct
14 Correct 3 ms 1996 KB Output is correct
15 Correct 1 ms 1612 KB Output is correct
16 Correct 1 ms 1704 KB Output is correct
17 Correct 2 ms 1700 KB Output is correct
18 Correct 1 ms 1740 KB Output is correct
19 Correct 2 ms 1740 KB Output is correct
20 Correct 1 ms 1740 KB Output is correct
21 Correct 2 ms 1740 KB Output is correct
22 Correct 2 ms 1740 KB Output is correct
23 Correct 2 ms 1868 KB Output is correct
24 Correct 2 ms 1868 KB Output is correct
25 Correct 2 ms 1996 KB Output is correct
26 Correct 2 ms 1996 KB Output is correct
27 Correct 2 ms 1996 KB Output is correct
28 Correct 2 ms 1996 KB Output is correct
29 Correct 2 ms 1996 KB Output is correct
30 Correct 2 ms 1996 KB Output is correct
31 Correct 2 ms 1996 KB Output is correct
32 Correct 2 ms 1996 KB Output is correct
33 Correct 12 ms 4052 KB Output is correct
34 Correct 12 ms 4172 KB Output is correct
35 Correct 41 ms 4164 KB Output is correct
36 Correct 17 ms 4524 KB Output is correct
37 Correct 19 ms 4472 KB Output is correct
38 Correct 48 ms 4460 KB Output is correct
39 Correct 26 ms 4932 KB Output is correct
40 Correct 21 ms 4936 KB Output is correct
41 Correct 59 ms 4940 KB Output is correct
42 Correct 25 ms 5304 KB Output is correct
43 Correct 22 ms 5272 KB Output is correct
44 Correct 77 ms 5316 KB Output is correct
45 Correct 33 ms 5700 KB Output is correct
46 Correct 27 ms 5724 KB Output is correct
47 Correct 93 ms 5700 KB Output is correct
48 Correct 34 ms 6084 KB Output is correct
49 Correct 32 ms 6084 KB Output is correct
50 Correct 105 ms 6168 KB Output is correct
51 Correct 38 ms 6568 KB Output is correct
52 Correct 39 ms 6576 KB Output is correct
53 Correct 135 ms 6580 KB Output is correct
54 Correct 48 ms 6904 KB Output is correct
55 Correct 44 ms 6948 KB Output is correct
56 Correct 156 ms 6920 KB Output is correct
57 Correct 49 ms 7368 KB Output is correct
58 Correct 47 ms 7364 KB Output is correct
59 Correct 184 ms 7312 KB Output is correct
60 Correct 63 ms 7760 KB Output is correct
61 Correct 55 ms 7804 KB Output is correct
62 Correct 202 ms 7868 KB Output is correct
63 Correct 155 ms 7856 KB Output is correct
64 Correct 299 ms 7860 KB Output is correct
65 Correct 295 ms 7860 KB Output is correct
66 Correct 244 ms 7760 KB Output is correct
67 Correct 175 ms 7856 KB Output is correct
68 Correct 96 ms 7876 KB Output is correct
69 Correct 95 ms 7800 KB Output is correct
70 Correct 88 ms 7788 KB Output is correct
71 Correct 89 ms 7972 KB Output is correct
72 Correct 67 ms 7772 KB Output is correct
73 Correct 77 ms 8012 KB Output is correct
74 Correct 114 ms 8132 KB Output is correct
75 Correct 129 ms 8100 KB Output is correct
76 Correct 144 ms 8136 KB Output is correct
77 Correct 139 ms 8132 KB Output is correct
78 Correct 134 ms 8024 KB Output is correct
79 Correct 141 ms 8108 KB Output is correct
80 Correct 137 ms 8108 KB Output is correct
81 Correct 159 ms 8084 KB Output is correct
82 Correct 136 ms 7996 KB Output is correct
83 Correct 137 ms 8004 KB Output is correct
84 Correct 144 ms 8080 KB Output is correct
85 Correct 152 ms 7948 KB Output is correct
86 Correct 163 ms 8072 KB Output is correct
87 Correct 150 ms 8076 KB Output is correct
88 Correct 142 ms 8048 KB Output is correct
89 Correct 166 ms 8040 KB Output is correct
90 Correct 174 ms 8004 KB Output is correct
91 Correct 176 ms 7952 KB Output is correct
92 Correct 178 ms 8016 KB Output is correct