Submission #1167142

#	Time	Username	Problem	Language	Result	Execution time	Memory
1167142		SmuggingSpun	Bootfall (IZhO17_bootfall)	C++20	13 / 100	1095 ms	492 KiB

bootfall

#include<bits/stdc++.h>
#define taskname "A"
using namespace std;
const int lim = 505;
int n, a_max, a_sum = 0, a[lim];
namespace sub123{
    const int LIM = 1e4 + 5;
    const int mod = 1e9 + 9;
    void add(int& a, int b){
        if((a += b) >= mod){
            a -= mod;
        }
    }
    void sub(int& a, int b){
        if((a -= b) < 0){
            a += mod;
        }
    }
    int dp[LIM];
    void add_item(int x){
        for(int i = a_sum; i >= x; i--){
            add(dp[i], dp[i - x]);
        }
    }
    void remove_item(int x){
        for(int i = x; i <= a_sum; i++){
            sub(dp[i], dp[i - x]);
        }
    }
    void solve(){
        memset(dp, 0, sizeof(dp));
        for(int i = dp[0] = 1; i <= n; i++){
            add_item(a[i]);
        }
        if((a_sum & 1) || dp[a_sum >> 1] == 0){
            return void(cout << 0);
        }
        vector<int>ans;
        for(int i = a_sum - a_max; i > 0; remove_item(i--)){
            add_item(i);
            ans.emplace_back(i);
            for(int j = 1; j <= n; j++){
                int sum = a_sum + i - a[j];
                if(sum & 1){
                    ans.pop_back();
                    break;
                }
                remove_item(a[j]);
                if(dp[sum >> 1] == 0){
                    add_item(a[j]);
                    ans.pop_back();
                    break;
                }
                add_item(a[j]);
            }
        }
        cout << ans.size() << "\n";
        for(int i = ans.size(); i > 0; ){
            cout << ans[--i] << " ";
        }
    }
}
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	if(fopen(taskname".inp", "r")){
		freopen(taskname".inp", "r", stdin);
	}
    cin >> n;
    for(int i = 1; i <= n; i++){
        cin >> a[i];
        a_sum += a[i];
    }
    a_max = *max_element(a + 1, a + n + 1);
    if(n <= 12 || (n <= 100 && a_max <= 100)){
        sub123::solve();
    }
}

Compilation message (stderr)

bootfall.cpp: In function 'int main()':
bootfall.cpp:66:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   66 |                 freopen(taskname".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

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