# | Submission time | Handle | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
259553 | 2020-08-08T02:24:46 Z | dantoh000 | Secret Permutation (RMI19_permutation) | C++14 | 0 ms | 0 KB |
#include <bits/stdc++.h> #include "permutationc.h" using namespace std; int n; int Query(vector<int> q){ int a[n]; for (int i = 0; i < n; i++){ a[i] = q[i]; } return query(a); } int d[257]; int vis[257]; int P[257]; bool findperm(int id){ if (id == n) return true; int last = P[id-1]; int dif = d[id]; //printf("%d: %d +- %d\n",id,last,dif); int cur = last+dif; if (cur >= 1 && cur <= n && !vis[cur]){ P[id] = cur; vis[cur] = 1; if (findperm(id+1)) return true; vis[cur] = 0; P[id] = 0; } cur = last-dif; if (cur >= 1 && cur <= n && !vis[cur]){ P[id] = cur; vis[cur] = 1; if (findperm(id+1)) return true; vis[cur] = 0; P[id] = 0; } return false; } void solve(int _N){ n = _N; vector<int> q; for (int i = 1; i <= n; i++){ q.push_back(i); } d[n] = Query(q); for (int j = n-1; j >= 1; j--){ q.insert(q.begin(),q.back()); q.pop_back(); d[j] = Query(q); } int sum = 0; for (int i = 1; i <= n; i++){ sum += d[i]; } assert(sum % (n-1) == 0); sum /= n-1; for (int i = 1; i <= n; i++){ d[i] = sum-d[i]; //printf("%d ",d[i]); //assert(d[i] == abs(ans[i-1]-ans[i%N])); } //printf("\n"); for (int i = 1; i <= n; i++){ vis[i] = 1; P[0] = i; if (findperm(1)){ int pos[n+1]; for (int i = 0; i < n; i++){ pos[P[i]] = i+1; } q.clear(); for (int i = 1; i <= n; i++){ q.push_back(pos[i]); } if (query(q) != n-1) reverse(P,P+n); answer(P); return; } vis[i] = 0; } }