Submission #1167149

#	Time	Username	Problem	Language	Result	Execution time	Memory
1167149		SmuggingSpun	Bootfall (IZhO17_bootfall)	C++20	44 / 100	123 ms	12720 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 sub12{
    const int LIM = 2500;
    void solve(){
        bitset<LIM>dp;
        dp.reset();
        dp.set(0);
        for(int i = 1; i <= n; i++){
            dp |= dp << a[i];
        }
        if((a_sum & 1) || !dp.test(a_sum >> 1)){
            return void(cout << 0);
        }
        vector<int>ans;
        for(int i = a_sum - a_max; i > 0; 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;
                }
                dp.reset();
                dp.reset(0);
                dp.set(i);
                sum >>= 1;
                for(int k = 1; k <= n; k++){
                    if(k != j){
                        dp |= dp << a[k];
                        if(dp.test(sum)){
                            break;
                        }
                    }
                }
                if(!dp.test(sum)){
                    ans.pop_back();
                    break;
                }
            }
        }
        cout << ans.size() << "\n";
        for(int i = ans.size(); i > 0; ){
            cout << ans[--i] << " ";
        }
    }
}
namespace sub3456{
    const int LIM = 25e4 + 1;
    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];
    bitset<LIM>imp[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);
        }
        for(int i = 1; i <= n; add_item(a[i++])){
            remove_item(a[i]);
            imp[i].reset();
            for(int j = 0; j <= a_sum; j++){
                if(dp[j] == 0){
                    imp[i].set(j);
                }
            }
        }
        vector<int>ans;
        for(int i = a_sum - a_max; i > 0; i--){
            ans.emplace_back(i);
            for(int j = 1; j <= n; j++){
                int sum = a_sum + i - a[j];
                if((sum & 1) || (imp[j].test(sum >>= 1) && (sum < i || imp[j].test(sum - i)))){
                    ans.pop_back();
                    break;
                }
            }
        }
        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 <= 30 && a_max <= 20)){
        sub12::solve();
    }
    else{
        sub3456::solve();
    }
}

Compilation message (stderr)

bootfall.cpp: In function 'int main()':
bootfall.cpp:113:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  113 |                 freopen(taskname".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

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