# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
72520 | (#118) | Key of Impassable Doors (FXCUP3_key) | 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>
#include"key.h"
using namespace std;
int sz[1005], lft[1005];
int out[1005], mb[1005];
vector<int> cycle[1005];
bool is_cycle(int i) {
if(lft[sz[i]] < sz[i]) return false;
vector<int> cand;
for(int j=i+1;j<=N;j++) {
if(sz[i] == sz[j] && !mb[j]) cand.push_back(j);
}
if(cand.size() == sz[i]-1) {
cand.push_back(i);
sort(cand.begin(), cand.end());
int x = cand[0];
for(int j : cand) {
cycle[x].push_back(j);
mb[j] = x;
}
} else {
vector<int> rcand;
random_shuffle(cand.begin(), cand.end());
for(int k=0; k<cand.size(); k++) {
TakeKey(i);
TakeKey(j);
int ret = Explore();
if(ret == sz[i]) rcand.push_back(j);
if(rcand.size() == sz[i]-1) break;
if(rcand.size() + cand.size() - k < sz[i]) break;
}
if(rcand.size() < sz[i]-1) return false;
rcand.push_back(i);
sort(rcand.begin(), rcand.end());
int x = rcand[0];
for(int j : rcand) {
cycle[x].push_back(j);
mb[j] = x;
}
}
return true;
}
bool is_tail(int i) {
vector<int> cand;
if(sz[i] == 2 || lft[sz[i]-1]) {
for(int j=1;j<=N;j++) {
if(sz[j] == sz[i]-1) cand.push_back(j);
}
random_shuffle(cand.begin(), cand.end());
for(int j : cand) {
TakeKey(i);
TakeKey(j);
int ret = Explore();
if(ret == sz[i]) {
out[i] = j;
return true;
}
}
}
return false;
}
mt19937 mt(random_device{}());
void EnsureKeyInfo(int N){
for(int i=1;i<=N;i++) {
TakeKey(i);
sz[i] = Explore();
if(sz[i] == 1) out[i] = i;
else lft[sz[i]]++;
}
for(int i=1;i<=N;i++) {
if(mb[i] || out[i]) continue;
if(mt()&1) {
if(is_tail(i)) {
lft[sz[i]]--;
continue;
}
is_cycle(i);
} else {
if(is_cycle(i)) {
lft[sz[i]] -= sz[i];
continue;
}
is_tail(i);
}
}
for(int i=1;i<=N;i++) {
if(mb[i]) {
if(cycle[i].empty()) continue;
for(int x : cycle[i]) {
for(int y : cycle[i]) {
Report(x,y);
}
}
} else {
int prv = i;
Report(i,i);
int x = out[i];
while(x != prv) {
if(mb[x]) {
for(int j : cycle[mb[x]]) {
Report(i, j);
}
break;
} else {
Report(i, x);
prv = x;
x = out[x];
}
}
}
}
}