Submission #92999

#	Time	Username	Problem	Language	Result	Execution time	Memory
92999		emil_physmath	Bootfall (IZhO17_bootfall)	C++17	6 / 100	9 ms	3960 KiB

bootfall

#include <iostream>
#include <stdio.h>
#include <algorithm>
#include <cstring>
#include <vector>
using namespace std;
const int MAXN=30;
const int MAXSUM=30*20;

int a[MAXN];
vector<int> sums[MAXN];

vector<int> AllPossSums(int arr[], int n);
int main()
{
	int n, sum=0;
	cin>>n;
	for (int i=0; i<n; i++)
		cin>>a[i];
	for (int i=0; i<n; i++)
	{
		sum+=a[i];
		swap(a[i], a[n-1]);
		sums[i]=AllPossSums(a, n-1);
		swap(a[i], a[n-1]);
	}
	vector<int> temp=AllPossSums(a, n);
	if (sum%2 || *lower_bound(temp.begin(), temp.end(), sum/2)!=sum/2)
	{
		cout<<"0\n";
		return 0;
	}
	vector<int> ans;
	for (int x=1; x<=sum; x++)
	{
		bool isAns=true;
		for (int i=0; i<n; i++)
		{
			if ((sum-a[i]+x)%2) {
				isAns=false;
				break;
			}
			auto it=lower_bound(sums[i].begin(), sums[i].end(), (sum-a[i]+x)/2-x);
			if (it==sums[i].end() || *it!=(sum-a[i]+x)/2-x) {
				isAns=false;
				break;
			}
		}
		if (isAns)
			ans.push_back(x);
	}
	cout<<ans.size()<<'\n';
	for (int i=0; i<ans.size(); i++)
		cout<<ans[i]<<' ';
	cout<<'\n';

	char I;
	cin >> I;
	return 0;
}

bool dp[MAXN][100*MAXSUM+1];
vector<int> AllPossSums(int arr[], int n)
{
	int sum=0;
	for (int i=0; i<n; i++)
		sum+=arr[i];
	memset(dp, 0, sizeof(dp));
	for (int i=0; i<=n; i++)
		dp[i][0]=true;
	for (int i=1; i<=n; i++)
	{
		dp[i][arr[i-1]]=true;
		for (int j=1; j<=sum; j++)
		{
			if (dp[i-1][j]==true)
			{
				dp[i][j]=true;
				dp[i][j+arr[i-1]]=true;
			}
		}
	}
	vector<int> res;
	for (int j=0; j<=sum; j++)
		if (dp[n][j]==true)
			res.push_back(j);
	return res;
}

Compilation message (stderr)

bootfall.cpp: In function 'int main()':
bootfall.cpp:53:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i=0; i<ans.size(); i++)
                ~^~~~~~~~~~~

• Subtask 1: 6 / 6
• Subtask 2: 0 / 7
• Subtask 3: 0 / 15
• Subtask 4: 0 / 16
• Subtask 5: 0 / 21
• Subtask 6: 0 / 35