Submission #663557

#	Time	Username	Problem	Language	Result	Execution time	Memory
663557		Ninja_Kunai	Bootfall (IZhO17_bootfall)	C++17	28 / 100	1089 ms	716 KiB

bootfall

/**
*    Author :  Nguyen Tuan Vu
*    Created : 27.11.2022
**/

#pragma GCC optimize("O3")
#pragma GCC target("avx,avx2,fma")
#include<bits/stdc++.h>
#define MASK(x) ((1)<<(x))
#define BIT(x, i) (((x)>>(i))&(1))
#define ALL(v)  (v).begin(), (v).end()
#define REP(i, n)  for (int i = 0, _n = (n); i < _n; ++i)
#define FOR(i, a, b)  for (int i = (a), _b = (b); i <= _b; ++i) 
#define FORD(i, b, a)  for (int i = (b), _a = (a); i >= _a; --i)
#define db(val) "["#val" = "<<(val)<<"] "
#define TIME  (1.0 * clock() / CLOCKS_PER_SEC)

template <class X, class Y> bool minimize(X &a, Y b) {
    if (a > b) return a = b, true;
    return false;
}
template <class X, class Y> bool maximize(X &a, Y b) {
    if (a < b) return a = b, true;
    return false;
}

using namespace std;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int Rand(int l, int r) {return l + rng() % (r - l + 1);}

void file(){
    #define TASK "TASK"
    if(fopen(TASK".in", "r")) {
        freopen(TASK".in", "r", stdin);
        freopen(TASK".out", "w", stdout);
    }
}

const int N = 5e2 + 5;
const int M = 5e2 * 5e2;
int n, a[N], b[N];
bitset <2 * M + 5> dp[2];

bitset <2 * M + 5> calc(int n) {
	dp[0].reset(); dp[1].reset();
	dp[0][M] = 1;
	REP(i, n) {
		if (dp[i & 1].count() == 0) break; 
		dp[(i + 1) & 1] |= dp[i & 1] << b[i + 1];
		dp[(i + 1) & 1] |= dp[i & 1] >> b[i + 1];

		dp[i & 1].reset();
	}

	return dp[n & 1];
}

int main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    file();
    cin >> n;
    FOR(i, 1, n) cin >> a[i], b[i] = a[i];
    if (calc(n)[M] == 0) return cout << 0, 0;
    bitset <2 * M + 5> tmp;
    FOR(i, 0, 2 * M) tmp[i] = 1;
    vector <int> ID;
    FOR(i, 1, n) ID.push_back(i);

    if (n <= 200) {
	    FOR(i, 1, n) {
	    	int cnt = 0;
	    	FOR(j, 1, n) if (i != j) b[++cnt] = a[j];
	    	tmp &= calc(n - 1);
	    	if (tmp.count() == 0) break;
	    }    	
    }
    else {
	    FOR(t, 1, n / 4) {
	    	int i = ID[t - 1];
	    	int cnt = 0;
	    	FOR(j, 1, n) if (i != j) b[++cnt] = a[j];
	    	tmp &= calc(n - 1);
	    	if (tmp.count() == 0) break;
	    }
	}

    vector <int> ans;
    FOR(i, 0, 2 * M) if (tmp[i]) ans.push_back(abs(i - M));
    sort (ALL(ans)); ans.erase(unique(ALL(ans)), ans.end());
    cout << ans.size() << '\n';
    for (auto x : ans) cout << x << ' ';
    cerr << "Time elapsed: " << TIME << " s.\n";
    return 0;
}

/*
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INPUT:                                            |
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OUTPUT:                                           |
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*/

Compilation message (stderr)

bootfall.cpp: In function 'void file()':
bootfall.cpp:35:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 |         freopen(TASK".in", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
bootfall.cpp:36:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |         freopen(TASK".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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