# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
505154 | rainliofficial | Xoractive (IZhO19_xoractive) | 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 "interactive.h"
//#include "grader.cpp"
using namespace std;
#define ll long long
#define pii pair<int, int>
#define f first
#define s second
multiset<int> filter(vector<int>& all, vector<int>& exclude){
multiset<int> allValues;
for (int i : all){
allValues.insert(i);
}
for (int i : exclude){
if (allValues.find(i) != allValues.end()){
allValues.erase(allValues.find(i));
}
}
return allValues;
}
vector<int> guess(int n) {
vector<int> ans(n);
vector<int> allPositions(n);
for (int i=0; i<n; i++){
allPositions[i] = i+1;
}
vector<int> exludeFirst(n-1);
for (int i=1; i<n; i++){
exludeFirst[i-1] = i+1;
}
int first = ask(1);
vector<int> allPairwiseXor = get_pairwise_xor(allPositions);
vector<int> excludeFirstXor = get_pairwise_xor(exludeFirst);
multiset<int> allValues = filter(allPairwiseXor, excludeFirstXor);
vector<int> valToInd(n+1); // Maps an element to its answer index
valToInd[first] = 1;
// Look at answer indexes by bit
int maxBits = log2(n)+1;
for (int i=0; i<=maxBits; i++){
vector<int> currSet; // The set of numbers with this bit ON
for (int j=2; j<=n; j++){
if (j & (1<<i)){ // This bit is ON
currSet.push_back(j);
}
}
if (currSet.empty()){
continue;
}
vector<int> currSetXor = get_pairwise_xor(currSet);
currSet.push_back(1);
vector<int> xorWithFirst = get_pairwise_xor(currSet);
multiset<int> currSetResult = filter(xorWithFirst, currSetXor);
set<int> processed;
for (int curr : currSetResult){
if (curr == 0 || processed.find(curr) != processed.end()){
continue;
}
processed.insert(curr);
int val = curr ^ first; // Convert XOR value to orig value
valToInd[val] += 1<<i;
}
}
for (int i=1; i<=n; i++){
ans[valToInd[i]-1] = i;
}
return ans;
}