| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 722292 | tvladm2009 | Secret Permutation (RMI19_permutation) | 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 "permutation.h"
using namespace std;
typedef long long ll;
const int N_MAX = 256;
mt19937 rnd(time(NULL));
vector <int> sol, questions;
bool used[N_MAX + 2];
bool found = 0;
void dfs(int pos, int N) {
if (pos == N - 1) {
if (abs(sol[0] - sol[pos]) == questions[pos]) {
found = 1;
}
return;
}
int next = sol[pos] - questions[pos];
if (1 <= next && next <= N && !used[next]) {
sol.push_back(next);
used[next] = 1;
dfs(pos + 1, N);
if (found == 1) {
return;
}
used[next] = 0;
sol.pop_back();
}
next = sol[pos] + questions[pos];
if (1 <= next && next <= N && !used[next]) {
sol.push_back(next);
used[next] = 1;
dfs(pos + 1, N);
if (found == 1) {
return;
}
used[next] = 0;
sol.pop_back();
}
}
void solve(int N) {
vector <int> V;
for (int i = 1; i <= N; i++) {
V.push_back(i);
}
random_shuffle(V.begin(), V.end(), rnd);
vector <int> C = V;
questions.clear();
for (int i = 1; i <= N; i++) {
rotate(V.begin(), V.begin() + 1, V.end());
questions.push_back(query(V));
}
int sum = 0;
for (int it : questions) {
sum += it;
}
sum /= N - 1;
for (int &it : questions) {
it = sum - it;
}
for (int i = 1; i <= N; i++) {
for (int j = 1; j <= N; j++) {
used[j] = 0;
}
sol.clear();
sol.push_back(i);
used[i] = 1;
found = 0;
dfs(0, N);
if (found == 1) {
vector <int> ret(N);
for (int j = 0; j < N; j++) {
ret[C[j] - 1] = sol[j];
}
answer(ret);
return;
}
}
}