#include <bits/stdc++.h> #define all(v) begin(v), end(v) #define ii pair<int, int> #define fi first #define se second using namespace std; const int MAXN = 805, MAXS = 1006, infINT = 1e9 + 234; const int dx[4] = {-1, 0, 0, +1}; const int dy[4] = {0, -1, +1, 0}; template<class X, class Y> bool minimize(X &x, const Y &y){return x > y ? x = y, 1: 0;} int numSize, maxRange, bee[MAXN][MAXN], mecho[MAXN][MAXN]; char board[MAXN][MAXN]; void input(){ cin >> numSize >> maxRange; for(int row = 1; row <= numSize; row++) for(int col = 1; col <= numSize; col++) cin >> board[row][col]; } bool isValid(int row, int col){ return 1 <= min(row, col) && max(row, col) <= numSize; } void bfsBee(){ #define PUSH(row, col, d) if (minimize(bee[row][col], d)) q.emplace(row, col) memset(bee, 0x3f, sizeof bee); queue<ii> q; for(int row = 1; row <= numSize; row++) for(int col = 1; col <= numSize; col++) if (board[row][col] == 'H') PUSH(row, col, 0); while(q.size()){ int row = q.front().fi, col = q.front().se; q.pop(); for(int k = 0; k < 4; k++){ int nrow = row + dx[k], ncol = col + dy[k]; if (isValid(nrow, ncol) && (board[nrow][ncol] == 'G' || board[nrow][ncol] == 'M')){ PUSH(nrow, ncol, bee[row][col] + 1); } } } } bool bfsMecho(const int &mid){ #define PUSH(row, col, d) if (minimize(mecho[row][col], d)) q.emplace(row, col) memset(mecho, 0x3f, sizeof mecho); queue<ii> q; for(int row = 1; row <= numSize; row++) for(int col = 1; col <= numSize; col++) if (board[row][col] == 'M' && bee[row][col] > mid) PUSH(row, col, 0); while(q.size()){ int row = q.front().fi, col = q.front().se; q.pop(); for(int k = 0; k < 4; k++){ int nrow = row + dx[k], ncol = col + dy[k]; if (isValid(nrow, ncol) && (board[nrow][ncol] == 'G' || board[nrow][ncol] == 'M' || board[nrow][ncol] == 'D')){ if ((mecho[row][col] + 1) / maxRange < bee[nrow][ncol] - mid) PUSH(nrow, ncol, mecho[row][col] + 1); } } } for(int row = 1; row <= numSize; row++) for(int col = 1; col <= numSize; col++) if (board[row][col] == 'D' && mecho[row][col] < infINT) return 1; return 0; } bool check(const int &mid){ return bfsMecho(mid); } void solve(){ bfsBee(); int l = 0, r = numSize * numSize, m, res = -1; while(l <= r){ m = (l + r) >> 1; if (check(m)) res = m, l = m + 1; else r = m - 1; } cout << res << '\n'; } int main(){ ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); #define task "test" if (fopen(task".inp", "r")){ freopen(task".inp", "r", stdin); freopen(task".out", "w", stdout); } input(); solve(); }

mecho.cpp:52: warning: "PUSH" redefined
   52 |     #define PUSH(row, col, d) if (minimize(mecho[row][col], d)) q.emplace(row, col)
      | 
mecho.cpp:31: note: this is the location of the previous definition
   31 |     #define PUSH(row, col, d) if (minimize(bee[row][col], d)) q.emplace(row, col)
      | 
mecho.cpp: In function 'int main()':
mecho.cpp:98:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   98 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
mecho.cpp:99:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   99 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~