#include<bits/stdc++.h>
using namespace std;
using i64 = long long;
#define all(x) x.begin(), x.end()
#define L(i, b, e) for (int i = b; i < e; ++i)
#define R(i, b, e) for (int i = b; i >= e; --i)
#define pb emplace_back
#define vi vector<int>
#define sz(x) ((int) x.size())
const int N = 8e2 + 7, Mx = 1e9 + 9;
const int dx[] = {1, -1, 0, 0}, dy[] = {0, 0, 1, -1};
int n, s;
string a[N];
int dis1[N][N], dis2[N][N];
pair<int, int> st, d;
bool in(int x, int y){
return (x >= 0 && y >= 0 && x < n && y < n && a[x][y] != 'T');
}
int work(int m){
L(i, 0, n)L(j, 0, n)dis2[i][j] = Mx;
queue<tuple<int, int, int>> q;
q.push({st.first, st.second, s});
dis2[st.first][st.second] = m;
while (!q.empty()){
auto [x, y, p] = q.front();
q.pop();
if (p == 0 && dis2[x][y] >= dis1[x][y])continue;
if (p == 0)p = s;
L(i, 0, 4){
int nx = x + dx[i], ny = y + dy[i];
if (in(nx, ny) && dis2[x][y] + (p == s) <= dis1[nx][ny] && dis2[nx][ny] == Mx && s[nx][ny] != 'H'){
q.push({nx, ny, p - 1});
dis2[nx][ny] = dis2[x][y] + (p == s);
}
}
}
return (dis2[d.first][d.second] != Mx);
}
int main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
cin >> n >> s;
L(i, 0, n){
cin >> a[i];
}
L(i, 0, n)L(j, 0, n)dis1[i][j] = dis2[i][j] = Mx;
queue<pair<int, int>> q;
L(i, 0, n){
L(j, 0, n){
if (a[i][j] == 'H'){
q.push({i, j});
dis1[i][j] = 0;
}else if (a[i][j] == 'M'){
st = {i, j};
}else if (a[i][j] == 'D'){
d = {i, j};
}
}
}
while (!q.empty()){
auto [x, y] = q.front();
q.pop();
L(i, 0, 4){
int nx = x + dx[i], ny = y + dy[i];
if (in(nx, ny) && a[nx][ny] != 'D' && dis1[nx][ny] == Mx){
q.push({nx, ny});
dis1[nx][ny] = dis1[x][y] + 1;
}
}
}
int lo = 0, hi = n * n, ans = -1;
while (lo <= hi){
int mid = lo + (hi - lo) / 2;
if (work(mid)){
ans = mid;
lo = mid + 1;
}else{
hi = mid - 1;
}
}
cout << ans;
}
Compilation message
mecho.cpp: In function 'int work(int)':
mecho.cpp:25:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
25 | auto [x, y, p] = q.front();
| ^
mecho.cpp:31:95: error: invalid types 'int[int]' for array subscript
31 | if (in(nx, ny) && dis2[x][y] + (p == s) <= dis1[nx][ny] && dis2[nx][ny] == Mx && s[nx][ny] != 'H'){
| ^
mecho.cpp: In function 'int main()':
mecho.cpp:62:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
62 | auto [x, y] = q.front();
| ^
