Submission #650099

#	Time	Username	Problem	Language	Result	Execution time	Memory
650099		mychecksedad	Mecho (IOI09_mecho)	C++17	24 / 100	447 ms	65536 KiB

mecho

/* Author : Mychecksdead */
#include<bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
typedef long long int ll;
typedef long double ld;
#define MOD (1000000000+7)
#define MOD1 (998244353)
#define PI 3.1415926535
#define pb push_back
#define setp() cout << setprecision(15)
#define all(x) x.begin(), x.end()
#define debug(x) cerr << #x << " is " << x << '\n';
const int N = 1e6+100, M = 1e5+10, F = 2147483646, K = 20;



int n, S, ax, ay, bx, by, dist[1000][1000], d[1000][1000], arr[4][2] = {{0, 1}, {0, -1}, {1, 0}, {-1, 0}};
string s[N];
bool vis[1000][1000];
void solve(){
    cin >> n >> S;
    queue<array<int, 2>> q, q1;
    for(int i = 0; i < n; ++i){
        cin >> s[i];
        for(int j = 0; j < n; ++j){
            dist[i][j] = d[i][j] = MOD;
            if(s[i][j] == 'H') q.push({i, j}), dist[i][j] = 0;
            else if(s[i][j] == 'M') q1.push({i, j}), d[i][j] = 0, bx = i, by = j;
            else if(s[i][j] == 'D') ax = i, ay = j;
        }
    } 
    while(!q.empty()){
        int x = q.front()[0], y = q.front()[1];
        q.pop();
        for(int i = 0; i < 4; ++i){
            int a = x + arr[i][0];
            int b = y + arr[i][1];
            if(a>=0&&a<n&&b>=0&&b<n&&s[a][b]=='D'){
                dist[a][b] = min(dist[a][b], dist[x][y] + 1);
            }
            if(a<0||b<0||a==n||b==n||(s[a][b]!='G'&&s[a][b]!='M')) continue;
            if(dist[a][b] > dist[x][y] + 1) {
                dist[a][b] = dist[x][y] + 1;
                q.push({a, b});
            }
        }
    }   
    while(!q1.empty()){
        int x = q1.front()[0], y = q1.front()[1];
        q1.pop();
        for(int i = 0; i < 4; ++i){
            for(int f = 1; f <= S; ++f){
                int a = x + f * arr[i][0];
                int b = y + f * arr[i][1];
                if(a<0||b<0||a>=n||b>=n||(s[a][b]!='G'&&s[a][b]!='M'&&s[a][b]!='D')||d[a][b] < d[x][y] + 1) break;
                d[a][b] = d[x][y] + 1;
                q1.push({a, b});
            }
        }
    }   
   
    int l = 0, r = n*n, ans = -1;
    while(l <= r){
        int m = (l+r)>>1;
        bool ok = 0;
        for(int i = 0; i < n; ++i) for(int j = 0; j < n; ++j) vis[i][j] = 0;
        q.push({ax, ay});
        vis[ax][ay] = 1;
        while(!q.empty()){  
            int x = q.front()[0], y = q.front()[1];
            q.pop();
            if(dist[x][y] - m <= d[x][y]){
                continue;
            }
            if(x == bx && y == by){
                ok = 1;
                break;
            }
            for(int i = 0; i < 4; ++i){
                for(int f = 1; f <= S; ++f){
                    int a = x + f * arr[i][0];
                    int b = y + f * arr[i][1];
                    if(a<0||b<0||a>=n||b>=n||(s[a][b]!='G'&&s[a][b]!='M')||vis[a][b]) break;
                    vis[a][b] = 1;
                    q.push({a, b});
                }
            }    
        }
        if(ok){
            ans = m;
            l = m + 1;
        }else r = m - 1;
    }
    cout << ans;
}





int main(){
    cin.tie(0); ios::sync_with_stdio(0);
    int T = 1, aa;
    // cin >> T;aa=T;
    while(T--){
        // cout << "Case #" << aa-T << ": ";
        solve();
        cout << '\n';
    }
    return 0;
 
}

Compilation message (stderr)

mecho.cpp: In function 'int main()':
mecho.cpp:105:16: warning: unused variable 'aa' [-Wunused-variable]
  105 |     int T = 1, aa;
      |                ^~

• Subtask 1: 24 / 100