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Submission #442475

# Submission time Handle Problem Language Result Execution time Memory
442475 2021-07-07T20:19:47 Z dawangk Mecho (IOI09_mecho) C++14
100 / 100
 214 ms 8804 KB 
#include <bits/stdc++.h>
using namespace std;
#define inputJunk ios_base::sync_with_stdio(0); cin.tie(0);
#define pb push_back
#define f first
#define s second
#define all(x) x.begin(), x.end()
#define debug cout<<"HERE"<<endl;
#define ell "\n"

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pi;
typedef pair<ll, ll> pll;
typedef pair<pi, int> trip;
typedef pair<pll, ll> tripll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pi> vpi;
typedef vector<pll> vpll;
typedef vector<trip> vtrip;

const int INF = 1e9+1212;
const ll P = 9973, M = 1e9+9;
const int MM = 8e2+5; int mod = 1e9+7;//998244353

int n, k, sx, sy, ex, ey, dist[MM][MM]; char grid[MM][MM];
queue<pi> q; pi dir[4] {{1, 0}, {-1, 0}, {0, 1}, {0, -1}};
pi step[MM][MM];

bool vv(int a){
    return a>=0&&a<n;
}

bool valid(int x, int y){
    return vv(x)&&vv(y)&&(grid[x][y]=='G'||grid[x][y]=='M')&dist[x][y]==INF;
}

bool dfs(int t){
    queue<pi> q;
    for(int i = 0;i<n;i++){
        for(int j = 0;j<n;j++){
            step[i][j] = {-1, 0};
        }
    }
    step[sx][sy] = {t, 0};
    q.push({sx, sy});
    while(!q.empty()){
        int x = q.front().f, y = q.front().s; q.pop();
        for(int i = 0;i<4;i++){
            int newx = x+dir[i].f, newy = y+dir[i].s;
            int newt = (step[x][y].s+1==k)?step[x][y].f+1:step[x][y].f;
            int newused = (step[x][y].s+1)%k;
            //cout<<newx<<" "<<newy<<endl;
            if(vv(newx)&&vv(newy)&&(grid[newx][newy]=='G'||grid[newx][newy]=='D')&&newt<dist[newx][newy]&&step[newx][newy].f==-1){

                step[newx][newy] = {newt, newused};
                q.push({newx, newy});
            }
        }
    }
    //cout<<t<<ell;
    /*
    for(int i = 0;i<n;i++){
        for(int j = 0;j<n;j++){
            cout<<"("<<step[i][j].f<<" "<<step[i][j].s<<")"<<" ";
        }cout<<ell;
    }*/
    return step[ex][ey].f!=-1;
}

int main(){
    inputJunk
    cin>>n>>k;
    for(int i = 0;i<n;i++){
        for(int j = 0;j<n;j++){
            cin>>grid[i][j];
            dist[i][j] = INF;
            if(grid[i][j]=='M'){sx = i; sy = j;}
            else if(grid[i][j]=='D'){ex = i;ey = j;}
            else if(grid[i][j]=='H'){q.push({i, j}); dist[i][j] = 0;}
        }
    }

    while(!q.empty()){
        int curx = q.front().f, cury = q.front().s;q.pop();
        //cout<<curx<<" "<<cury<<" "<<endl;
        for(int i = 0;i<4;i++){
            int newx = curx+dir[i].f, newy = cury+dir[i].s;
            if(valid(newx, newy)){
                dist[newx][newy] = dist[curx][cury]+1;
                q.push({newx, newy});
            }
        }
    }
/*
    for(int i = 0;i<n;i++){
        for(int j = 0;j<n;j++){
            cout<<dist[i][j]<<" ";
        }cout<<ell;
    }*/
    dist[ex][ey] = INF;
    int lo = 0, hi = 10000000;
    if(!dfs(0)){
        cout<<-1<<endl;
        return 0;
    }
    //cout<<"BOB"<<dfss(2)<<ell;

    while(lo<hi){
        //cout<<lo<<" "<<hi<<endl;
        int mid = (lo+hi+1)/2;
        if(mid<dist[sx][sy]&&dfs(mid)){
            lo = mid;
        }else{
            hi = mid-1;
        }
    }
    cout<<lo<<endl;

}
/*CUSTOM TEST CASE 1
*/

/*CUSTOM TEST CASE 2
*/

/*CUSTOM TEST CASE 3
*/

/*Comments of Shame
- floating error (use integer division instead)
- cin vs getline
- upperbound and lowerbound returns iteratorsf
- use long long when number is big enough
- for dp invalid cases needs to be skipped
- some base cases won't work (review cow poetry)
- always check bounds, some TLE are due to incorrect bounds!
- dont mess up return types
= RESET ARRAYS!!!!!!!!!!
- USE UR BRAIN
- INF setting problems
*/
/*
    freopen("time.in","r", stdin);
    freopen("time.out","w", stdout);
*/

Compilation message

mecho.cpp: In function 'bool valid(int, int)':
mecho.cpp:36:71: warning: suggest parentheses around comparison in operand of '&' [-Wparentheses]
   36 |     return vv(x)&&vv(y)&&(grid[x][y]=='G'||grid[x][y]=='M')&dist[x][y]==INF;
      |                                                             ~~~~~~~~~~^~~~~

Subtask #1
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 332 KB Output is correct
2 Correct 0 ms 332 KB Output is correct
3 Correct 0 ms 332 KB Output is correct
4 Correct 0 ms 332 KB Output is correct
5 Correct 1 ms 332 KB Output is correct
6 Correct 0 ms 332 KB Output is correct
7 Correct 131 ms 8516 KB Output is correct
8 Correct 1 ms 332 KB Output is correct
9 Correct 0 ms 332 KB Output is correct
10 Correct 0 ms 332 KB Output is correct
11 Correct 1 ms 332 KB Output is correct
12 Correct 1 ms 796 KB Output is correct
13 Correct 1 ms 716 KB Output is correct
14 Correct 1 ms 844 KB Output is correct
15 Correct 1 ms 460 KB Output is correct
16 Correct 1 ms 460 KB Output is correct
17 Correct 1 ms 460 KB Output is correct
18 Correct 1 ms 460 KB Output is correct
19 Correct 1 ms 460 KB Output is correct
20 Correct 1 ms 460 KB Output is correct
21 Correct 1 ms 588 KB Output is correct
22 Correct 1 ms 588 KB Output is correct
23 Correct 1 ms 716 KB Output is correct
24 Correct 1 ms 716 KB Output is correct
25 Correct 1 ms 716 KB Output is correct
26 Correct 1 ms 716 KB Output is correct
27 Correct 1 ms 844 KB Output is correct
28 Correct 1 ms 844 KB Output is correct
29 Correct 1 ms 844 KB Output is correct
30 Correct 1 ms 844 KB Output is correct
31 Correct 1 ms 844 KB Output is correct
32 Correct 1 ms 844 KB Output is correct
33 Correct 9 ms 3896 KB Output is correct
34 Correct 11 ms 3788 KB Output is correct
35 Correct 31 ms 3788 KB Output is correct
36 Correct 10 ms 4300 KB Output is correct
37 Correct 10 ms 4332 KB Output is correct
38 Correct 41 ms 4300 KB Output is correct
39 Correct 12 ms 4912 KB Output is correct
40 Correct 14 ms 4908 KB Output is correct
41 Correct 53 ms 4812 KB Output is correct
42 Correct 16 ms 5324 KB Output is correct
43 Correct 17 ms 5440 KB Output is correct
44 Correct 65 ms 5388 KB Output is correct
45 Correct 23 ms 5944 KB Output is correct
46 Correct 24 ms 5836 KB Output is correct
47 Correct 80 ms 5848 KB Output is correct
48 Correct 21 ms 6360 KB Output is correct
49 Correct 23 ms 6404 KB Output is correct
50 Correct 96 ms 6452 KB Output is correct
51 Correct 24 ms 6908 KB Output is correct
52 Correct 30 ms 6960 KB Output is correct
53 Correct 120 ms 6872 KB Output is correct
54 Correct 37 ms 7432 KB Output is correct
55 Correct 34 ms 7436 KB Output is correct
56 Correct 156 ms 7372 KB Output is correct
57 Correct 43 ms 7980 KB Output is correct
58 Correct 40 ms 7880 KB Output is correct
59 Correct 162 ms 7988 KB Output is correct
60 Correct 35 ms 8464 KB Output is correct
61 Correct 38 ms 8468 KB Output is correct
62 Correct 188 ms 8412 KB Output is correct
63 Correct 135 ms 8504 KB Output is correct
64 Correct 206 ms 8500 KB Output is correct
65 Correct 214 ms 8388 KB Output is correct
66 Correct 169 ms 8464 KB Output is correct
67 Correct 44 ms 8388 KB Output is correct
68 Correct 67 ms 8492 KB Output is correct
69 Correct 67 ms 8476 KB Output is correct
70 Correct 65 ms 8616 KB Output is correct
71 Correct 54 ms 8516 KB Output is correct
72 Correct 44 ms 8412 KB Output is correct
73 Correct 56 ms 8740 KB Output is correct
74 Correct 110 ms 8776 KB Output is correct
75 Correct 102 ms 8772 KB Output is correct
76 Correct 102 ms 8744 KB Output is correct
77 Correct 101 ms 8736 KB Output is correct
78 Correct 45 ms 8648 KB Output is correct
79 Correct 103 ms 8672 KB Output is correct
80 Correct 93 ms 8716 KB Output is correct
81 Correct 103 ms 8804 KB Output is correct
82 Correct 99 ms 8696 KB Output is correct
83 Correct 119 ms 8712 KB Output is correct
84 Correct 123 ms 8644 KB Output is correct
85 Correct 119 ms 8712 KB Output is correct
86 Correct 119 ms 8676 KB Output is correct
87 Correct 125 ms 8708 KB Output is correct
88 Correct 130 ms 8660 KB Output is correct
89 Correct 147 ms 8660 KB Output is correct
90 Correct 139 ms 8660 KB Output is correct
91 Correct 132 ms 8648 KB Output is correct
92 Correct 125 ms 8752 KB Output is correct