#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define ll long long
#define pll pair<ll, ll>
#define pii pair<int, int>
#define mp(x, y) make_pair(x, y)
#define sz(v) ((int) (v).size())
#define all(v) (v).begin(), (v).end()
#define MASK(i) (1LL << (i))
#define BIT(x, y) (((x) >> (y)) & 1)
#define clz __builtin_clzll
#define ctz __builtin_ctzll
#define popcount __builtin_popcount
#define lg(x) (63 - clz(x))
template <class X, class Y>
inline bool maximize(X &x, Y y) {
if (x < y) return x = y, true;
return false;
}
template <class X, class Y>
inline bool minimize(X &x, Y y) {
if (x > y) return x = y, true;
return false;
}
template <class X>
inline void compress(vector<X> &a) {
sort(all(a)); a.resize(unique(all(a)) - a.begin());
}
const ll oo = (ll) 1e17;
const int inf = (int) 1e9, mod = (int) 1e9 + 7;
struct Info {
int x, y;
char dir;
};
const int mxn = (int) 2e3 + 5, lg = (int) 19;
int r, c;
char a[mxn][mxn];
int f[mxn][mxn];
Info trace[mxn][mxn];
int dx[] = {0, 0, 1, -1};
int dy[] = {1, -1, 0, 0};
char d[] = {'>', '<', 'v', '^'};
bool isIn(int x, int y) {
return 1 <= x && x <= r && 1 <= y && y <= c;
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
cin >> r >> c;
for (int i = 1; i <= r; ++i)
for (int j = 1; j <= c; ++j)
cin >> a[i][j];
pair<int, int> s, t;
for (int i = 1; i <= r; ++i)
for (int j = 1; j <= c; ++j) {
if (a[i][j] == 'o')
s = mp(i, j);
else if (a[i][j] == 'x')
t = mp(i, j);
}
memset(f, 0x3f, sizeof f);
deque<pii> dq;
dq.push_back(s);
f[s.fi][s.se] = 0;
trace[s.fi][s.se] = {-1, -1, '!'};
while (!dq.empty()) {
pii top = dq.front(); dq.pop_front();
int u = top.fi, v = top.se;
if (top == t) continue;
for (int i = 0; i < 4; ++i) {
int x = u + dx[i];
int y = v + dy[i];
if (!isIn(x, y)) continue;
if (a[u][v] != '.' && (d[i] == a[u][v] || a[u][v] == 'o')) {
if (minimize(f[x][y], f[u][v])) {
trace[x][y] = {u, v, d[i]};
dq.push_front(mp(x, y));
}
} else {
if (minimize(f[x][y], f[u][v] + 1)) {
trace[x][y] = {u, v, d[i]};
dq.push_back(mp(x, y));
}
}
}
}
int u = t.fi, v = t.se;
cout << f[u][v] << '\n';
while (trace[u][v].x != -1) {
int x = trace[u][v].x;
int y = trace[u][v].y;
if (mp(x, y) != s)
a[x][y] = trace[u][v].dir;
u = x; v = y;
}
for (int i = 1; i <= r; ++i)
for (int j = 1; j <= c; ++j)
cout << a[i][j] << (j == c ? "\n" : "");
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
6 ms |
16988 KB |
Output is correct |
2 |
Correct |
5 ms |
16988 KB |
Output is correct |
3 |
Correct |
6 ms |
16984 KB |
Output is correct |
4 |
Correct |
6 ms |
16984 KB |
Output is correct |
5 |
Correct |
6 ms |
16988 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
6 ms |
16988 KB |
Output is correct |
2 |
Correct |
5 ms |
16988 KB |
Output is correct |
3 |
Correct |
6 ms |
16984 KB |
Output is correct |
4 |
Correct |
6 ms |
16984 KB |
Output is correct |
5 |
Correct |
6 ms |
16988 KB |
Output is correct |
6 |
Correct |
46 ms |
26448 KB |
Output is correct |
7 |
Correct |
43 ms |
29524 KB |
Output is correct |
8 |
Correct |
110 ms |
40276 KB |
Output is correct |
9 |
Correct |
167 ms |
56408 KB |
Output is correct |
10 |
Correct |
267 ms |
66896 KB |
Output is correct |
11 |
Correct |
280 ms |
78204 KB |
Output is correct |