// #pragma GCC optimize("Ofast", "unroll-loops")
#include <bits/stdc++.h>
using namespace std;
// #define int long long
#define double long double
using pii = pair<int, int>;
template<typename T>
using prior = priority_queue<T, vector<T>, greater<T>>;
template<typename T>
using Prior = priority_queue<T>;
#define X first
#define Y second
#define ALL(x) (x).begin(), (x).end()
#define eb emplace_back
#define pb push_back
#define fastIO() ios_base::sync_with_stdio(false), cin.tie(0)
const int INF = 1E9;
const int maxn = 4E6 + 50;
const int dx[] = {0, 1, 0, -1};
const int dy[] = {1, 0, -1, 0};
const char dc[] = ">v<^";
int n, m;
vector<string> mp;
vector<int> dis(maxn, INF), lst(maxn, -1);
prior<pii> pq;
auto trans = [&](int x, int y) {return x * m + y;};
auto valid = [&](int x, int y) {return x >= 0 and x < n and y >= 0 and y < m;};
void dijkstra(int now) {
int i = now / m, j = now % m;
for (int d = 0; d < 4; ++d) {
if (!valid(i+dx[d], j+dy[d])) continue;
int val = mp[i][j] == dc[d] or mp[i][j] == 'o' ? 0 : 1;
int id = trans(i+dx[d], j+dy[d]);
if (dis[id] > dis[now] + val) {
dis[id] = dis[now] + val, lst[id] = now;
pq.push({dis[id], id});
}
}
while (!pq.empty()) {
auto [val, id] = pq.top(); pq.pop();
if (val == dis[id]) dijkstra(id);
}
}
void solve() {
cin >> n >> m, mp.resize(n);
for (auto &str : mp) cin >> str;
int st, ed;
for (int i = 0; i < n; ++i) {
for (int j = 0; j < m; ++j) {
if (mp[i][j] == 'o') st = trans(i, j);
if (mp[i][j] == 'x') ed = trans(i, j);
}
}
dis[st] = 0, dijkstra(st);
// cout << st << " " << ed << "\n";
// for (int i = 0; i < n*m; ++i) cout << dis[i] << " \n"[(i+1) % m == 0];
int nx = ed / m, ny = ed % m, now = ed;
while ((now = trans(nx, ny)) != st) {
/// >v<^ --- 0 <-> 2; 1 <-> 3 ///
// cout << nx << " " << ny << "\n";
for (int d = 0; d < 4; ++d) {
if (trans(nx+dx[d], ny+dy[d]) != lst[now]) continue;
nx = lst[now] / m, ny = lst[now] % m;
if (mp[nx][ny] != 'o') mp[nx][ny] = dc[d^2];
break;
}
}
cout << dis[ed] << "\n";
for (auto str : mp) cout << str << "\n";
}
int32_t main() {
// fastIO();
int t = 1; // cin >> t;
while (t--) solve();
return 0;
}
Compilation message
Main.cpp:33:15: error: non-local lambda expression cannot have a capture-default
33 | auto trans = [&](int x, int y) {return x * m + y;};
| ^
Main.cpp:34:15: error: non-local lambda expression cannot have a capture-default
34 | auto valid = [&](int x, int y) {return x >= 0 and x < n and y >= 0 and y < m;};
| ^
