#include <iostream>
#include <vector>
#include <cmath>
using namespace std;
#define pii pair<int, int>
vector<vector<int>>vec;
vector<bool>visit;
void dfs(int v) {
visit[v] = true;
for (int i = 0; i < vec[v].size(); i++) {
if (!visit[vec[v][i]])
dfs(vec[v][i]);
}
}
int main() {
int r, c, n;
cin >> r >> c >> n;
set<pii>green;
int a, b;
for (int i = 0; i < n; i++) {
cin >> a >> b;
a--, b--;
green.insert({ a,b });
}
vec.resize(r * c);
visit.resize(r * c, false);
for (int i = 0; i < r; i++) {
for (int j = 0; j < c; j++) {
if (green.find({ i,j }) != green.end()) {
if(i!=r-1)
vec[i * c + j].push_back(i * c + j + 1);
if(j!=c-1)
vec[i * c + j].push_back((i + 1) * c + j);
}
else {
if(j!=c-1)
vec[i * c + j].push_back(i * c + j + 1);
}
}
}
int t;
cin >> t;
while (t--) {
int y1, x1, y2, x2;
cin >> y1 >> x1 >> y2 >> x2;
y1--, x1--, y2--, x2--;
dfs(y1 * c + x1);
if (visit[y2 * c + x2])
cout << "YES";
else
cout << "NO";
cout << endl;
for (int i = 0; i < r * c; i++)
visit[i] = false;
}
}
Compilation message
trampoline.cpp: In function 'void dfs(int)':
trampoline.cpp:10:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
10 | for (int i = 0; i < vec[v].size(); i++) {
| ~~^~~~~~~~~~~~~~~
trampoline.cpp: In function 'int main()':
trampoline.cpp:18:2: error: 'set' was not declared in this scope
18 | set<pii>green;
| ^~~
trampoline.cpp:4:1: note: 'std::set' is defined in header '<set>'; did you forget to '#include <set>'?
3 | #include <cmath>
+++ |+#include <set>
4 | using namespace std;
trampoline.cpp:18:9: error: expected primary-expression before '>' token
18 | set<pii>green;
| ^
trampoline.cpp:18:10: error: 'green' was not declared in this scope
18 | set<pii>green;
| ^~~~~
