Submission #1175922

#	Time	Username	Problem	Language	Result	Execution time	Memory
1175922		Haanhtien	Bootfall (IZhO17_bootfall)	C++17	13 / 100	1 ms	328 KiB

bootfall

#include<bits/stdc++.h>
using namespace std;

#define ll long long
#define FOR(i, a, b) for(int i=(a), _b=(b); i<=_b; i++)
#define FORD(i, a, b) for(int i=(a), _b=(b); i>=_b; i--)
#define BIT(i, j) ((i>>j)&1)
#define pb push_back
#define ii pair<ll, ll>
#define pii pair<ll, ii>
#define all(x) x.begin(), x.end()
#define fi first
#define se second

const ll inf = 1e18;
const ll mod = 1e9+7;
const ll N = 505;
const ll M = 50005;

int n, a[N], ans, sum, bit[N * N], f[N * N], res[N * N];
void solve()
{
    cin >> n;
    for (int i = 1; i <= n; i++)
    {
        cin >> a[i];
        sum += a[i];
    }
    ll half = sum/2;
    f[0] = 1;
    for (int i = 1; i <= n; i++)
    {
        for (int j = sum; j >= a[i]; j--)
        {
            f[j] += f[j - a[i]];
        }
    }
    if (sum % 2 != 0 || f[sum/2] == 0)
    {
        cout << 0;
        return;
    }
    fill(res, res + sum + 1, 1);
    for (int i = 1; i <= n; i++)
    {
        ll tmp = sum - a[i];
        fill(bit, bit + sum + 1, 0);
        
        for (int j = a[i]; j <= sum; j++)
        {
            f[j] -= f[j - a[i]];
        }
        for (int A = 1; A <= sum; A++)
        {
            if (f[A] > 0) 
            {
                ll B = tmp - A;
                ll x = abs(A - B);
                bit[x] = 1;
            }
        }
        for (int k = 1; k <= sum; k++) res[k] &= bit[k];
        for (int j = sum; j >= a[i]; j--)
        {
            f[j] += f[j - a[i]];
        }
    }
    vector<int> v;
    for (int i = 1; i <= sum; i++)
    {
        if (res[i]) v.pb(i);
    }
    cout << v.size() << '\n';
    for (auto i : v) cout <<i << ' ';
    
}
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    #define task "task"
    if(fopen(task".inp", "r"))
    {
        freopen(task".INP", "r", stdin);
        freopen(task".OUT", "w", stdout);
    }

    if(fopen("task.inp", "r"))
    {
        freopen("task.INP", "r", stdin);
        freopen("task.OUT", "w", stdout);
    }

    solve();
    return 0;
}

Compilation message (stderr)

bootfall.cpp: In function 'int main()':
bootfall.cpp:83:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   83 |         freopen(task".INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bootfall.cpp:84:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   84 |         freopen(task".OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
bootfall.cpp:89:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   89 |         freopen("task.INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bootfall.cpp:90:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   90 |         freopen("task.OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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