#include <bits/stdc++.h>
using namespace std;
#define fast ios::sync_with_stdio(0);cin.tie(0);
#define s second
#define f first
typedef long long ll;
const ll MOD = 1e9 + 7;
const ll LOGN = 18;
const ll MAXN = 1e5 + 100;
vector<pair<int,pair<int,int>>> graph[2005][2005], rev[2005][2005];
int dist[2005][2005], vis[2005][2005];
vector<string> grid;
pair<int,int> s, e;
void change(int row, int col, int nrow, int ncol) {
if (row < 0 || col < 0 || grid[0].size() <= row || grid[0].size() <= col)
return ;
if (nrow > row)
grid[row][col] = 'v';
else if (nrow < row)
grid[row][col] = '^';
else if (ncol < col)
grid[row][col] = '<';
else
grid[row][col] = '>';
}
void dfs(int row, int col, int target) {
vis[row][col] = true;
for (auto u : rev[row][col]) {
int w = u.f;
int nrow = u.s.f;
int ncol = u.s.s;
if (vis[nrow][ncol])
continue;
if (dist[nrow][ncol] + w == target) {
change(nrow, ncol, row, col);
dfs(nrow, ncol, target - w);
return ;
}
}
}
int r, c;
bool check(int row, int col) {
if (row >= 0 && col >= 0 && r > row && c > col)
return true;
return false;
}
int main() {
fast
cin >> r >> c;
for (int i = 0; i < 2005; i++) {
for (int j = 0; j < 2005; j++)
dist[i][j] = 1e8;
}
grid = vector<string>(r);
for (int i = 0; i < r; i++)
cin >> grid[i];
for (int i = 0; i < r; i++) {
for (int j = 0; j < c; j++) {
if (grid[i][j] == '>') {
if (check(i, j+1)) {
graph[i][j].push_back({0, {i, j+1}});
rev[i][j+1].push_back({0, {i, j}});
}
if (check(i+1, j)) {
graph[i][j].push_back({1, {i+1, j}});
rev[i+1][j].push_back({1, {i, j}});
}
if (check(i, j-1)) {
graph[i][j].push_back({1, {i, j-1}});
rev[i][j-1].push_back({1, {i, j}});
}
if (check(i-1, j)) {
graph[i][j].push_back({1, {i-1, j}});
rev[i-1][j].push_back({1, {i, j}});
}
} else if (grid[i][j] == '<') {
if (check(i, j+1)) {
graph[i][j].push_back({1, {i, j+1}});
rev[i][j+1].push_back({1, {i, j}});
}
if (check(i+1, j)) {
graph[i][j].push_back({1, {i+1, j}});
rev[i+1][j].push_back({1, {i, j}});
}
if (check(i, j-1)) {
graph[i][j].push_back({0, {i, j-1}});
rev[i][j-1].push_back({0, {i, j}});
}
if (check(i-1, j)) {
graph[i][j].push_back({1, {i-1, j}});
rev[i-1][j].push_back({1, {i, j}});
}
} else if (grid[i][j] == 'v') {
if (check(i, j+1)) {
graph[i][j].push_back({1, {i, j+1}});
rev[i][j+1].push_back({1, {i, j}});
}
if (check(i+1, j)) {
graph[i][j].push_back({0, {i+1, j}});
rev[i+1][j].push_back({0, {i, j}});
}
if (check(i, j-1)) {
graph[i][j].push_back({1, {i, j-1}});
rev[i][j-1].push_back({1, {i, j}});
}
if (check(i-1, j)) {
graph[i][j].push_back({1, {i-1, j}});
rev[i-1][j].push_back({1, {i, j}});
}
} else if (grid[i][j] == '^') {
if (check(i, j+1)) {
graph[i][j].push_back({1, {i, j+1}});
rev[i][j+1].push_back({1, {i, j}});
}
if (check(i+1, j)) {
graph[i][j].push_back({1, {i+1, j}});
rev[i+1][j].push_back({1, {i, j}});
}
if (check(i, j-1)) {
graph[i][j].push_back({1, {i, j-1}});
rev[i][j-1].push_back({1, {i, j}});
}
if (check(i-1, j)) {
graph[i][j].push_back({0, {i-1, j}});
rev[i-1][j].push_back({0, {i, j}});
}
} else if (grid[i][j] == '.') {
if (check(i, j+1)) {
graph[i][j].push_back({1, {i, j+1}});
rev[i][j+1].push_back({1, {i, j}});
}
if (check(i+1, j)) {
graph[i][j].push_back({1, {i+1, j}});
rev[i+1][j].push_back({1, {i, j}});
}
if (check(i, j-1)) {
graph[i][j].push_back({1, {i, j-1}});
rev[i][j-1].push_back({1, {i, j}});
}
if (check(i-1, j)) {
graph[i][j].push_back({1, {i-1, j}});
rev[i-1][j].push_back({1, {i, j}});
}
} else if (grid[i][j] == 'o') {
s = {i, j};
if (check(i, j+1)) {
graph[i][j].push_back({0, {i, j+1}});
rev[i][j+1].push_back({0, {i, j}});
}
if (check(i+1, j)) {
graph[i][j].push_back({0, {i+1, j}});
rev[i+1][j].push_back({0, {i, j}});
}
if (check(i, j-1)) {
graph[i][j].push_back({0, {i, j-1}});
rev[i][j-1].push_back({0, {i, j}});
}
if (check(i-1, j)) {
graph[i][j].push_back({0, {i-1, j}});
rev[i-1][j].push_back({0, {i, j}});
}
} else
e = {i, j};
}
}
deque<pair<int,int>> dq;
dq.push_back(s);
dist[s.f][s.s] = 0;
while (!dq.empty()) {
int row = dq.front().f;
int col = dq.front().s;
dq.pop_front();
for (auto u : graph[row][col]) {
int w = u.f;
int nrow = u.s.f;
int ncol = u.s.s;
if (dist[nrow][ncol] > w + dist[row][col]) {
dist[nrow][ncol] = w + dist[row][col];
if (w == 1)
dq.push_back({nrow, ncol});
else
dq.push_front({nrow, ncol});
}
}
}
cout << dist[e.f][e.s] << "\n";
memset(vis, 0, sizeof(vis));
dfs(e.f, e.s, dist[e.f][e.s]);
grid[s.f][s.s] = 'o';
for (int i = 0; i < r; i++)
cout << grid[i] << "\n";
}
Compilation message
Main.cpp: In function 'void change(int, int, int, int)':
Main.cpp:17:46: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
17 | if (row < 0 || col < 0 || grid[0].size() <= row || grid[0].size() <= col)
| ~~~~~~~~~~~~~~~^~~~~~
Main.cpp:17:71: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
17 | if (row < 0 || col < 0 || grid[0].size() <= row || grid[0].size() <= col)
| ~~~~~~~~~~~~~~~^~~~~~
Main.cpp:17:5: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
17 | if (row < 0 || col < 0 || grid[0].size() <= row || grid[0].size() <= col)
| ^~
Main.cpp:20:2: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
20 | if (nrow > row)
| ^~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
46 ms |
220496 KB |
Output is correct |
2 |
Partially correct |
45 ms |
220500 KB |
Partially correct |
3 |
Partially correct |
44 ms |
220756 KB |
Partially correct |
4 |
Correct |
45 ms |
220760 KB |
Output is correct |
5 |
Correct |
46 ms |
220500 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
46 ms |
220496 KB |
Output is correct |
2 |
Partially correct |
45 ms |
220500 KB |
Partially correct |
3 |
Partially correct |
44 ms |
220756 KB |
Partially correct |
4 |
Correct |
45 ms |
220760 KB |
Output is correct |
5 |
Correct |
46 ms |
220500 KB |
Output is correct |
6 |
Partially correct |
184 ms |
284496 KB |
Partially correct |
7 |
Correct |
202 ms |
287616 KB |
Output is correct |
8 |
Partially correct |
462 ms |
384592 KB |
Partially correct |
9 |
Correct |
710 ms |
494932 KB |
Output is correct |
10 |
Runtime error |
529 ms |
524288 KB |
Execution killed with signal 9 |
11 |
Halted |
0 ms |
0 KB |
- |