Submission #700119

#	Time	Username	Problem	Language	Result	Execution time	Memory
700119		fdnfksd	Bootfall (IZhO17_bootfall)	C++14	100 / 100	395 ms	3420 KiB

bootfall

#include<bits/stdc++.h>
#define task "C"
#define ll long long
#define ld long double
#define fi first
#define se second
#define pb push_back
using namespace std;
const int MAXN = 5e2 + 5;
const ll INF = 1e18 + 5;
const int MOD = 1e9 + 22071997;

int n;
int a[MAXN], sum = 0;

void Input()
{
    cin >> n;
    for (int i = 1; i <= n; i++)
    {
        cin >> a[i];
        sum += a[i];
    }
}

int dp[MAXN * MAXN], chk[MAXN * MAXN];


void Solve()
{
    if (sum % 2)
    {
        cout << 0;
        return;
    }
    dp[0] = 1;
    for (int i = 1; i <= n; i++)
    {
        for (int j = sum; j >= a[i]; j--)
        {
            dp[j]+=dp[j - a[i]];
            if(dp[j]>=MOD) dp[j]-=MOD;
        }
    }
    if (!dp[sum / 2])
    {
        cout << 0;
        return;
    }

    for (int i = 1; i <= n; i++)
    {
        for (int j = a[i]; j <= sum; j++)
        {
            dp[j]-= dp[j - a[i]];
            if(dp[j]<0) dp[j]+=MOD;
        }
        for (int j = 0; j <= (sum - a[i]) / 2; j++)
        {
            chk[sum - j - a[i] - j] += dp[j] > 0;
        }
        for (int j = sum; j >= a[i]; j--)
        {
            dp[j]+=dp[j - a[i]];
            if(dp[j]>=MOD) dp[j]-=MOD;
        }
    }

    vector<int> res;
    for (int i = 0; i <= sum; i++)
        if (chk[i] == n)
            res.pb(i);

    cout << res.size() << '\n';
    for (int id : res)
        cout << id << ' ';
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    if (fopen(task".INP","r"))
    {
        freopen(task".INP","r",stdin);
        //freopen(task".OUT","w",stdout);
    }
    Input();
    Solve();
}

Compilation message (stderr)

bootfall.cpp: In function 'int main()':
bootfall.cpp:85:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   85 |         freopen(task".INP","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

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