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Submission #287391

# Submission time Handle Problem Language Result Execution time Memory
287391 2020-08-31T16:38:26 Z eohomegrownapps Secret Permutation (RMI19_permutation) C++14
60 / 100
 61 ms 388 KB 
#include "permutation.h"
#include <bits/stdc++.h>
using namespace std;

//int query(std::vector<int> v);
//void answer(std::vector<int> v);

vector<int> getDifferences(vector<int> perm){
	deque<int> dq(perm.begin(),perm.end());
	int n = perm.size();

	vector<int> vals(n);
	int tot = 0;
	for (int i = 0; i<n; i++){
		vector<int> q(dq.begin(),dq.end());
		/*for (int x : q){
			cout<<x<<' ';
		}cout<<endl;*/
		vals[i]=query(q);
		tot+=vals[i];
		dq.push_back(dq.front());
		dq.pop_front();
	}
	vector<int> ans(n);
	ans[n-1]=tot/(n-1) - vals[0];
	//cout<<ans[n-1]<<'\n';
	int prev = ans[n-1];
	vals.push_back(vals[0]);
	for (int i = 0; i<n; i++){
		ans[i] = prev - (vals[i+1]-vals[i]);
		prev = ans[i];
	}
	return ans;
}

vector<bool> used;
stack<int> minv;
stack<int> maxv;
vector<int> values;
vector<int> v1;
vector<int> v1ans;
int curv = 0;
int nv;
int evals = 0;
bool rec(int ind){
	evals++;
	if (evals>1000000){
		return false;
	}
	/*cout<<ind<<endl;
	for (int i : values){
		cout<<i<<' ';
	}cout<<endl;*/
	// add element ind
	if (ind==nv){
		if (v1ans[0]!=-1){
			return false;
		}
		if (abs(values[nv-1]-values[0])==v1[nv-1]){
			v1ans = v1;
			/*cout<<"solution:"<<endl;
			for (int i : values){
				cout<<i<<' ';
			}cout<<'\n';*/
			return true;
		}
		return true;
	}
	//used[nv+x]
	//can we add?
	bool works = true;
	int qtmp = values[ind-1]+v1[ind-1];
	//cout<<"check increase "<<qtmp<<endl;
	if (max(qtmp,maxv.top())-minv.top()<nv && !used[nv+qtmp]){
		// try it
		bool popfrom = false;
		if (qtmp>maxv.top()){
			popfrom = true;
			maxv.push(qtmp);
		}
		values[ind]=qtmp;
		used[nv+qtmp]=true;
		if (!rec(ind+1)){
			works = false;
		}
		used[nv+qtmp]=false;
		if (popfrom){
			maxv.pop();
		}
	}
	if (!works){
		return false;
	}
	v1[ind-1]=-v1[ind-1];
	qtmp = values[ind-1]+v1[ind-1];
	//cout<<"check decrease "<<qtmp<<endl;
	if (maxv.top()-min(qtmp,minv.top())<nv && !used[nv+qtmp]){
		// try it
		bool popfrom = false;
		if (qtmp<minv.top()){
			popfrom = true;
			minv.push(qtmp);
		}
		values[ind]=qtmp;
		used[nv+qtmp]=true;
		if (!rec(ind+1)){
			works = false;
		}
		used[nv+qtmp]=false;
		if (popfrom){
			minv.pop();
		}
	}
	v1[ind-1]=-v1[ind-1];
	return works;
}

void solve(int n){
	vector<int> q1(n);
	for (int i = 0; i<n; i++){
		q1[i]=i+1;
	}
	v1 = getDifferences(q1);
	/*for (int i : v){
		cout<<i<<' ';
	}cout<<endl;*/
	vector<int> q2;
	for (int i = 1; i<=n; i+=2){
		q2.push_back(i);
	}
	for (int i = 2; i<=n; i+=2){
		q2.push_back(i);
	}

	used.resize(2*n+1);
	used[n]=true;
	values.resize(n);
	v1ans.resize(n,-1);
	nv = n;
	minv.push(0);
	maxv.push(0);
	bool rc = rec(1);
	//cout<<rc<<'\n';

	if (rc!=1){
		for (int i = 0; i<n; i++){
			v1[i]=abs(v1[i]);
		}
		vector<int> v2 = getDifferences(q2);
		for (int i = 0; i<n-1; i++){
			int tot;
			if (i%2==0){
				//cout<<"query "<<i/2<<'\n';
				tot = v2[i/2];
			} else {
				//cout<<"query "<<(n+1)/2+i/2<<'\n';
				tot = v2[(n+1)/2+i/2];
			}
			//cout<<tot<<'\n';
			//cout<<v1[i]<<' '<<v1[i+1]<<'\n';
			if (abs(v1[i]+v1[i+1])!=tot){
				v1[i+1]=-v1[i+1];
			}
		}
	} else {
		v1 = v1ans;
	}
	/*for (int i : v1){
		cout<<i<<' ';
	}cout<<endl;*/
	int cur = 0;
	int mn = 0;
	for (int i = 0; i<n-1; i++){
		cur+=v1[i];
		mn=min(cur,mn);
	}
	vector<int> ans(n);
	ans[0]=1-mn;
	for (int i = 1; i<n; i++){
		ans[i]=ans[i-1]+v1[i-1];
	}
	/*for (int i : ans){
		cout<<i<<' ';
	}cout<<'\n';*/
	answer(ans);
}

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
9.0 / 15.0

# Verdict Execution time Memory Grader output
1 Partially correct 1 ms 256 KB Partially correct
2 Partially correct 0 ms 256 KB Partially correct
3 Partially correct 1 ms 256 KB Partially correct
4 Partially correct 0 ms 256 KB Partially correct
5 Partially correct 1 ms 384 KB Partially correct
6 Partially correct 1 ms 256 KB Partially correct

Subtask #2
21.0 / 35.0

# Verdict Execution time Memory Grader output
1 Partially correct 1 ms 256 KB Partially correct
2 Partially correct 0 ms 256 KB Partially correct
3 Partially correct 1 ms 256 KB Partially correct
4 Partially correct 0 ms 256 KB Partially correct
5 Partially correct 1 ms 384 KB Partially correct
6 Partially correct 1 ms 256 KB Partially correct
7 Partially correct 2 ms 256 KB Partially correct
8 Partially correct 2 ms 256 KB Partially correct
9 Partially correct 2 ms 384 KB Partially correct
10 Partially correct 2 ms 256 KB Partially correct
11 Partially correct 2 ms 256 KB Partially correct
12 Partially correct 3 ms 256 KB Partially correct
13 Partially correct 3 ms 256 KB Partially correct
14 Partially correct 2 ms 256 KB Partially correct
15 Partially correct 2 ms 256 KB Partially correct
16 Partially correct 3 ms 360 KB Partially correct

Subtask #3
30.0 / 50.0

# Verdict Execution time Memory Grader output
1 Partially correct 1 ms 256 KB Partially correct
2 Partially correct 0 ms 256 KB Partially correct
3 Partially correct 1 ms 256 KB Partially correct
4 Partially correct 0 ms 256 KB Partially correct
5 Partially correct 1 ms 384 KB Partially correct
6 Partially correct 1 ms 256 KB Partially correct
7 Partially correct 2 ms 256 KB Partially correct
8 Partially correct 2 ms 256 KB Partially correct
9 Partially correct 2 ms 384 KB Partially correct
10 Partially correct 2 ms 256 KB Partially correct
11 Partially correct 2 ms 256 KB Partially correct
12 Partially correct 3 ms 256 KB Partially correct
13 Partially correct 3 ms 256 KB Partially correct
14 Partially correct 2 ms 256 KB Partially correct
15 Partially correct 2 ms 256 KB Partially correct
16 Partially correct 3 ms 360 KB Partially correct
17 Partially correct 22 ms 376 KB Partially correct
18 Partially correct 29 ms 384 KB Partially correct
19 Partially correct 28 ms 384 KB Partially correct
20 Partially correct 24 ms 384 KB Partially correct
21 Partially correct 48 ms 376 KB Partially correct
22 Partially correct 54 ms 384 KB Partially correct
23 Partially correct 35 ms 384 KB Partially correct
24 Partially correct 52 ms 388 KB Partially correct
25 Partially correct 61 ms 384 KB Partially correct
26 Partially correct 22 ms 376 KB Partially correct