Submission #1262952

#	Time	Username	Problem	Language	Result	Execution time	Memory
1262952		dhuyyyy	Mecho (IOI09_mecho)	C++20	1 / 100	1095 ms	11332 KiB

mecho

#include <bits/stdc++.h>
#define fi first
#define se second
#define int long long
using namespace std;

using ll = long long;
using ii = pair<int,int>;
using pii = pair<int,ii>;
using aa = array<int,4>;

const int N = 805;
const int INF = 1e9;
const int MOD = 1e9+21;

int n,S,c,u,v,start_x,start_y,home_x,home_y;
int ans = -1,cur = -1;
ii d[N][N];
int dx[4] = {1,0,-1,0};
int dy[4] = {0,1,0,-1};
char a[N][N];
queue<aa> q;

bool ok(int i,int j){
    return min(i,j) >= 1 && max(i,j) <= n && a[i][j] != 'H' && a[i][j] != 'T';
}
signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL); cout.tie(NULL);
    cin >> n >> S;
    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= n; j++){
            cin >> a[i][j];
            if (a[i][j] == 'M'){ //Mecho pos
                start_x = i;
                start_y = j;
            }
            if (a[i][j] == 'H'){ //Hives pos
                q.push({i,j,0});
            }
            if (a[i][j] == 'D'){
                home_x = i;
                home_y = j;
            }
        }
    }
    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= n; j++) d[i][j] = {0,-1};
    }
    while (!q.empty()){
        c = q.front()[2];
        if (c != cur){
            queue<ii> qq;
            qq.push({start_x,start_y});
            d[start_x][start_y] = {0,c};
            while (!qq.empty()){
                tie(u,v) = qq.front();
                qq.pop();
                for (int k = 0; k < 4; k++){
                    int x = u + dx[k];
                    int y = v + dy[k];
                    if (ok(x,y) && d[x][y].se == cur){
                        d[x][y] = {d[u][v].fi + 1,c};
                        qq.push({x,y});
                    }
                }
            }
            if (d[home_x][home_y].se == cur){
                cout << ans;
                return 0;
            }
            ans = max(ans,c - (d[home_x][home_y].fi + S - 1) / S + 1);
            cur = c;
        }
        u = q.front()[0];
        v = q.front()[1];
        q.pop();
        for (int k = 0; k < 4; k++){
            int x = u + dy[k];
            int y = v + dy[k];
            if (ok(x,y) && a[x][y] != 'D'){
                a[x][y] = 'H';
                q.push({x,y,c+1});
            }
        }
    }
    cout << ans;
    return 0;
}

• Subtask 1: 1 / 100