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Submission #287405

# Submission time Handle Problem Language Result Execution time Memory
287405 2020-08-31T16:42:53 Z eohomegrownapps Secret Permutation (RMI19_permutation) C++14
60 / 100
 640 ms 384 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>20000000){
		return false;
	}
	/*cout<<ind<<endl;
	for (int i : values){
		cout<<i<<' ';
	}cout<<endl;*/
	// add element ind
	if (ind==nv){
		if (abs(values[nv-1]-values[0])==v1[nv-1]){
			/*cout<<"solution:"<<endl;
			for (int i : values){
				cout<<i<<' ';
			}cout<<'\n';*/
			if (v1ans[0]!=-1){
				return false;
			}
			v1ans = v1;
			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;
	}
	if (ind==1){
		return true;
	}
	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==false){
		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 Correct 1 ms 256 KB Output is correct
2 Partially correct 1 ms 384 KB Partially correct
3 Correct 0 ms 256 KB Output is correct
4 Correct 1 ms 256 KB Output is correct
5 Correct 0 ms 256 KB Output is correct
6 Correct 1 ms 256 KB Output is correct

Subtask #2
21.0 / 35.0

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

Subtask #3
30.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 256 KB Output is correct
2 Partially correct 1 ms 384 KB Partially correct
3 Correct 0 ms 256 KB Output is correct
4 Correct 1 ms 256 KB Output is correct
5 Correct 0 ms 256 KB Output is correct
6 Correct 1 ms 256 KB Output is correct
7 Correct 2 ms 256 KB Output is correct
8 Correct 1 ms 256 KB Output is correct
9 Correct 1 ms 256 KB Output is correct
10 Correct 2 ms 256 KB Output is correct
11 Correct 1 ms 256 KB Output is correct
12 Correct 1 ms 256 KB Output is correct
13 Correct 1 ms 256 KB Output is correct
14 Correct 1 ms 384 KB Output is correct
15 Correct 1 ms 256 KB Output is correct
16 Correct 1 ms 256 KB Output is correct
17 Correct 11 ms 384 KB Output is correct
18 Correct 16 ms 384 KB Output is correct
19 Correct 18 ms 384 KB Output is correct
20 Correct 13 ms 384 KB Output is correct
21 Correct 93 ms 384 KB Output is correct
22 Correct 65 ms 384 KB Output is correct
23 Correct 20 ms 376 KB Output is correct
24 Partially correct 640 ms 384 KB Partially correct
25 Correct 53 ms 384 KB Output is correct
26 Correct 11 ms 384 KB Output is correct