| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 892855 | shoryu386 | Trampoline (info1cup20_trampoline) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define MAXN 400007
vector<int> adj[MAXN];
bitset<MAXN> bs[MAXN];
bool vis[MAXN];
void dfs(int u) {
for(int v: adj[u]) {
if(!vis[v]) {
vis[v] = 1;
dfs(v);
}
bs[u] |= bs[v];
}
}
main(){
int r, c, n; cin >> r >> c >> n;
//r and c are useless lmao
int N = 0;
map<int, set< pair<int, bool> >> importantPts; int a, b;
for (int x = 0; x < n; x++){
cin >> a >> b;
importantPts[a].insert({b, 1}); //1 indicating green trampoline
N++;
}
int q; cin >> q;
pair<int, int> starts[q], ends[q];
for (int x = 0; x < q; x++){
cin >> starts[x].first >> starts[x].second >> ends[x].first >> ends[x].second;
importantPts[ends[x].first].insert({ends[x].second, 0});
N++;
}
map<pair<int, int>, int> coordToNode;
pair<int, int> hmm[N];
int cnt = 0;
for (auto y : importantPts){
for (auto z : y.second){
coordToNode[{y.first, z.first}] = cnt;
hmm[cnt] = {y.first, z.first};
cnt++;
}
}
for (auto y : importantPts){ //gen DAG
pair<int, int> lastCoords = {-1, -1};
for (auto z : y.second){
if (lastCoords.first != -1) adj[coordToNode[lastCoords]].push_back(coordToNode[{y.first, z.first}]);
auto lb = importantPts[y.first+1].lower_bound({z.first, 0});
if (lb != importantPts[y.first+1].end()){
adj[coordToNode[{y.first, z.first}]].push_back(coordToNode[{y.first+1, lb->first}]);
}
lastCoords = {y.first, z.first};
}
}
for (int i = 0; i < N; i++) bs[i][i] = 1;
for (int i = 0; i < N; i++) {
if (vis[i]) continue;
vis[i] = 1;
dfs(i);
}
for (int x = 0; x < q; x++){
auto startTramp = importantPts[starts[x].first].lower_bound({starts[x].second, 0});
if (startTramp == importantPts[starts[x].first].end()){
cout << "No\n"; continue;
}
int startF = starts[x].first, startS = startTramp->first;
if (bs[coordToNode[{startF, startS}]][coordToNode[{ends[x].first, ends[x].second}]]){
cout << "Yes\n";
}
else cout << "No\n";
}
}