Submission #340682

#	Time	Username	Problem	Language	Result	Execution time	Memory
340682		IZhO_2021_I_want_Silver	Bootfall (IZhO17_bootfall)	C++14	100 / 100	799 ms	3692 KiB

bootfall

#include <iostream>
#include <algorithm>
#include <vector>
#include <cmath>
#include <set>
#include <map>
#include <iomanip>
#include <cassert>
#include <stack>
#include <queue>
#include <bitset>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>-

using namespace std;
//using namespace __gnu_pbds;

typedef long long ll;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;

// template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
//  order_of_key (k) : Number of items strictly smaller than k .
//  find_by_order(k) : K-th element in a set (counting from zero).
#define sz(a) (int)a.size()
#define all(a) a.begin(), a.end()
#define pb push_back
#define ppb pop_back
#define mkp make_pair
#define F first
#define S second
#define lb lower_bound
#define ub upper_bound
#define show(a) cerr << #a <<" -> "<< a <<" "
#define nl cerr <<"\n"
//#define int ll

const int N = 3e5 + 5;

int n, a[N], sum, dp[N], cnt[N];
bitset <N> was;
vector <int> ans;

void add(int x) {
    sum += x;
    for (int i = sum; i >= x; --i) {
        dp[i] += dp[i - x];
    }
}
void del(int x) {
    for (int i = x; i <= sum; ++i) {
        dp[i] -= dp[i - x];
    }
    sum -= x;
}

void solve() {
    cin >> n;

    dp[0] = 1;
    for (int i = 1; i <= n; ++i) {
        cin >> a[i];
        add(a[i]);
    }

    bool exist_answer = 0;
    for (int j = 0; j <= sum; ++j) {
        if (dp[j] && sum - j == j) { exist_answer = 1; break; }
    }
    if (!exist_answer) { cout << 0; return; }

    for (int i = 1; i <= n; ++i) {
        del(a[i]);
        for (int j = 0; j <= sum; ++j) {
            if (dp[j]) {
                int Tima = max(sum - j, j) - min(sum - j, j);
                if(!was[Tima]) { ++cnt[Tima]; was[Tima] = 1; }
            }
        }
        for (int j = 0; j <= sum; ++j) { was[j] = 0; }
        add(a[i]);
    }
    for (int i = 1; i < sum; ++i) {
        if (cnt[i] == n) { ans.pb(i); }
    }
    cout << sz(ans) <<"\n";
    for (int i = 0; i < sz(ans); ++i) { cout << ans[i] <<" "; }
}

 main () {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	int tests = 1;
	//cin >> tests;
	while (tests --) {
		solve();
	}
	return 0;
}
/*
    Just Chalish!
*/

Compilation message (stderr)

bootfall.cpp:90:8: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   90 |  main () {
      |        ^

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