oj.uz

Submission #685501

# Submission time Handle Problem Language Result Execution time Memory
685501 2023-01-24T12:50:06 Z vovamr Secret Permutation (RMI19_permutation) C++17
50 / 100
 5000 ms 316 KB 
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include "permutation.h"
#pragma GCC optimize("-O3")
#pragma GCC optimize("unroll-loops")
#define fi first
#define se second
#define ll long long
#define ld long double
#define sz(x) ((int)(x).size())
#define all(x) 	(x).begin(), (x).end()
#define pb push_back
#define mpp make_pair
#define ve vector
using namespace std;
using namespace __gnu_pbds;
template<class T> using oset = tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
const ll inf = 1e18; const int iinf = 1e9;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
template <typename T> inline bool chmin(T& a, T b) { return (a > b ? a = b, 1 : 0); }
template <typename T> inline bool chmax(T& a, T b) { return (a < b ? a = b, 1 : 0); }

const int N = 300;

int nn;
ve<int> perm;

int p[N];
int res[N], df[N], used[N];

const int Z = 1;

ve<ve<int>> rnd_perm;
ve<int> rnd_res;

inline void rec(int pos) {
	if (pos == nn - 1) {
		int dif = df[0];
		if (abs(p[0] - p[nn - 1]) != dif) {
			return;
		}

		ve<int> res(nn), ress(nn);
		for (int i = 0; i < nn; ++i) res[perm[i] - 1] = p[i];
		for (int i = 0; i < nn; ++i) ress[i] = res[i];

		for (int id = 0; id < Z; ++id) {

			ve<int> pe = rnd_perm[id];

			int ans_jury = rnd_res[id];
			int ans_mine = 0;
			for (int i = 0; i < nn - 1; ++i) {
				ans_mine += abs( ress[pe[i] - 1] - ress[pe[i + 1] - 1] );
			}
			if (ans_jury != ans_mine) {
				return;
			}
		}

		answer(ress);
	}

	int cur = p[pos];
	int dif = df[(pos + 1) % nn];

	if (cur + dif >= 1 && cur + dif <= nn && !used[cur + dif]) {
		used[cur + dif] = 1;
		p[pos + 1] = cur + dif;
		rec(pos + 1);
		p[pos + 1] = -1;
		used[cur + dif] = 0;
	}

	if (cur - dif >= 1 && cur - dif <= nn && !used[cur - dif]) {
		used[cur - dif] = 1;
		p[pos + 1] = cur - dif;
		rec(pos + 1);
		p[pos + 1] = -1;
		used[cur - dif] = 0;
	}
}

void solve(int n) {
	if (n == 1) {
		answer(ve<int>{1});
	}

	perm.resize(n);
	iota(all(perm), 1);

	int I = n * (n - 1) / 2;

	int ivl = I / 2;
	int ivr = min(I, (int)((double)I * 1.5));

	while (1) {
		shuffle(all(perm), rng);
		int inv = 0;
		for (int i = 0; i < n; ++i) {
			for (int j = i + 1; j < n; ++j) {
				inv += (perm[i] > perm[j]);
			}
		}
		if (inv >= ivl && inv <= ivr) break;
	}

	rnd_res.resize(Z);
	rnd_perm.resize(Z);

	nn = n;
	ve<int> pe(n);
	for (int i = 0; i < n; ++i) {
		for (int c = 0; c < n; ++c) {
			pe[c] = perm[(i + c) % n];
		}
		res[i] = query(pe);
	}
	rnd_perm[0] = perm;
	rnd_res[0] = res[0];

	for (int id = 1; id < Z; ++id) {
		ve<int> pe(n);
		iota(all(pe), 1);
		shuffle(all(pe), rng);
		rnd_perm[id] = pe;
		rnd_res[id] = query(pe);
	}

	int s = accumulate(res, res + n, 0);
	for (int i = 0; i < n; ++i) {
		df[i] = (s / (n - 1)) - res[i];
	}

	ve<int> F(n);
	iota(all(F), 1);
	shuffle(all(F), rng);
	for (const auto &i : F) {
		int dif = df[1];
		if ((i + dif >= 1 && i + dif <= n) || (i - dif >= 1 && i - dif <= n)) {
			p[0] = i;
			used[i] = 1;
			rec(0);
			used[i] = 0;
			p[0] = -1;
		}
	}
}

#ifdef LOCAL
namespace A {
  int N;
  const int MAX_N = 1000;
  int P[1 + MAX_N];
  int queries = 0;
  
  void readInput() {
    //printf("The permutation you have to guess is:\n");
    scanf("%d", &N);
    for (int i = 1; i <= N; i++) {
      scanf("%d", &P[i]);
      //printf("%d ", P[i]);
    }
    //printf("\n");
  }
  
  int query(int V[]) {
    queries++;
    printf("query(");
    for (int i = 0; i < N - 1; i++) {
      printf("%d, ", V[i]);
    }
    printf("%d) = ", V[N - 1]);
    int freq[1 + N];
    for (int i = 0; i <= N; i++) {
      freq[i] = 0;
    }
    for (int i = 0; i < N; i++) {
      freq[V[i]]++;
    }
    for (int i = 1; i <= N; i++) {
      assert(freq[i] == 1);
    }
		int answer = 0;
    for (int i = 0; i + 1 < N; i++) {
      answer += abs(P[V[i + 1]] - P[V[i]]);
    }
    printf("%d\n", answer);
    fflush(stdout);
		return answer;
	}

	void answer(int V[]) {
		bool ok = true;
		ve<int> p(N);
		iota(all(p), 1);
		do {
			int ans_jury = 0;
			for (int i = 0; i < N - 1; ++i) ans_jury += abs(P[p[i]] - P[p[i + 1]]);
			int ans_mine = 0;
			for (int i = 0; i < N - 1; ++i) ans_mine += abs(V[p[i] - 1] - V[p[i + 1] - 1]);
			ok &= (ans_jury == ans_mine);
			if (!ok) break;
		} while (next_permutation(all(p)));
		if (ok) {
		  printf("Correct! with N = %d, Q = %d\n", N, queries);
		} else {
		  printf("Wrong answer!\n");
		}
		exit(0);
	}
}

int query(int p[]) {
	return A::query(p);
}

void answer(int ans[]) {
  A::answer(ans);
}

int query(std::vector<int> v) {
  int array[A::N];
  for (int i = 0; i < A::N; i++) {
    array[i] = v[i];
  }
  return query(array);
}

void answer(std::vector<int> v) {
  int array[A::N];
  for (int i = 0; i < A::N; i++) {
    array[i] = v[i];
  }
  answer(array);
}

int main(int argc, char **argv) {
  A::readInput();
  solve(A::N);
  return 0;
}
#endif

Compilation message

stub.cpp: In function 'int query(int*)':
stub.cpp:15:9: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |   fscanf(stdin, "%d", &x);
      |   ~~~~~~^~~~~~~~~~~~~~~~~
stub.cpp: In function 'int main(int, char**)':
stub.cpp:48:9: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |   fscanf(stdin, "%d", &N);
      |   ~~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 208 KB Output is correct
2 Correct 1 ms 208 KB Output is correct
3 Correct 1 ms 208 KB Output is correct
4 Correct 1 ms 208 KB Output is correct
5 Correct 1 ms 208 KB Output is correct
6 Correct 0 ms 208 KB Output is correct

Subtask #2
35.0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 208 KB Output is correct
2 Correct 1 ms 208 KB Output is correct
3 Correct 1 ms 208 KB Output is correct
4 Correct 1 ms 208 KB Output is correct
5 Correct 1 ms 208 KB Output is correct
6 Correct 0 ms 208 KB Output is correct
7 Correct 2 ms 208 KB Output is correct
8 Correct 1 ms 208 KB Output is correct
9 Correct 1 ms 208 KB Output is correct
10 Correct 1 ms 208 KB Output is correct
11 Correct 1 ms 208 KB Output is correct
12 Correct 1 ms 208 KB Output is correct
13 Correct 1 ms 208 KB Output is correct
14 Correct 1 ms 208 KB Output is correct
15 Correct 2 ms 208 KB Output is correct
16 Correct 1 ms 208 KB Output is correct

Subtask #3
0.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 208 KB Output is correct
2 Correct 1 ms 208 KB Output is correct
3 Correct 1 ms 208 KB Output is correct
4 Correct 1 ms 208 KB Output is correct
5 Correct 1 ms 208 KB Output is correct
6 Correct 0 ms 208 KB Output is correct
7 Correct 2 ms 208 KB Output is correct
8 Correct 1 ms 208 KB Output is correct
9 Correct 1 ms 208 KB Output is correct
10 Correct 1 ms 208 KB Output is correct
11 Correct 1 ms 208 KB Output is correct
12 Correct 1 ms 208 KB Output is correct
13 Correct 1 ms 208 KB Output is correct
14 Correct 1 ms 208 KB Output is correct
15 Correct 2 ms 208 KB Output is correct
16 Correct 1 ms 208 KB Output is correct
17 Correct 508 ms 308 KB Output is correct
18 Correct 1589 ms 308 KB Output is correct
19 Correct 487 ms 316 KB Output is correct
20 Execution timed out 5056 ms 216 KB Time limit exceeded
21 Halted 0 ms 0 KB -