Submission #648713

#	Time	Username	Problem	Language	Result	Execution time	Memory
648713		ghostwriter	Bootfall (IZhO17_bootfall)	C++14	100 / 100	719 ms	3472 KiB

bootfall

#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include <debug.h>
#else
#define debug(...)
#endif
#define ft front
#define bk back
#define st first
#define nd second
#define ins insert
#define ers erase
#define pb push_back
#define pf push_front
#define _pb pop_back
#define _pf pop_front
#define lb lower_bound
#define ub upper_bound
#define mtp make_tuple
#define bg begin
#define ed end
#define all(x) (x).bg(), (x).ed()
#define sz(x) (int)(x).size()
typedef long long ll; typedef unsigned long long ull;
typedef double db; typedef long double ldb;
typedef pair<int, int> pi; typedef pair<ll, ll> pll;
typedef vector<int> vi; typedef vector<ll> vll; typedef vector<pi> vpi; typedef vector<pll> vpll;
typedef string str;
template<typename T> T gcd(T a, T b) { return (b == 0? a : gcd(b, a % b)); }
template<typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }
#define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
#define FOS(i, r, l) for (int (i) = (r); (i) >= (l); --(i))
#define FRN(i, n) for (int (i) = 0; (i) < (n); ++(i))
#define FSN(i, n) for (int (i) = (n) - 1; (i) >= 0; --(i))
#define EACH(i, x) for (auto &(i) : (x))
#define WHILE while
#define file "TEST"
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
ll rand(ll l, ll r) { return uniform_int_distribution<ll>(l, r)(rd); }
/*
----------------------------------------------------------------
    END OF TEMPLATE
----------------------------------------------------------------
    Tran The Bao - ghostwriter
    Training for VOI23 gold medal
----------------------------------------------------------------
    DIT ME CHUYEN BAO LOC
----------------------------------------------------------------
*/
const int M = 1e9 + 7;
const int N = 502;
const int NxN = 25e4 + 1;
int n, a[N], c[NxN], d[NxN], sum = 0;
vi ans;
void add(int x) { FOS(i, NxN - 1, x) d[i] = (d[i] + d[i - x]) % M; }
void del(int x) { FOR(i, x, NxN - 1) d[i] = (d[i] - d[i - x] + M) % M; }
signed main() {
    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    // freopen(file".inp", "r", stdin);
    // freopen(file".out", "w", stdout);
    cin >> n;
    FOR(i, 1, n) {
    	cin >> a[i];
    	sum += a[i];
    }
    if (sum & 1) {
    	cout << 0;
    	return 0;
    }
    d[0] = 1;
    FOR(i, 1, n) add(a[i]);
    if (!d[sum / 2]) {
    	cout << 0;
    	return 0;
    }
    FOR(i, 1, NxN - 1) c[i] = 1;
    FOR(i, 1, n) {
    	del(a[i]);
    	FOR(j, 1, NxN - 1) {
    		if (!c[j]) continue;
    		int tmp = sum - a[i] + j;
    		if (tmp & 1) {
    			c[j] = 0;
    			continue;
    		}
    		if (!d[tmp / 2]) c[j] = 0;
    	}
    	add(a[i]);
    }
    FOR(i, 1, NxN - 1)
    	if (c[i])
    		ans.pb(i);
    cout << sz(ans) << '\n';
    EACH(i, ans) cout << i << ' ';
    return 0;
}
/*
4
1 3 1 5
----------------------------------------------------------------
From Benq:
    stuff you should look for
        * int overflow, array bounds
        * special cases (n=1?)
        * do smth instead of nothing and stay organized
        * WRITE STUFF DOWN
        * DON'T GET STUCK ON ONE APPROACH
----------------------------------------------------------------
*/

Compilation message (stderr)

bootfall.cpp: In function 'void add(int)':
bootfall.cpp:33:31: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   33 | #define FOS(i, r, l) for (int (i) = (r); (i) >= (l); --(i))
      |                               ^
bootfall.cpp:56:19: note: in expansion of macro 'FOS'
   56 | void add(int x) { FOS(i, NxN - 1, x) d[i] = (d[i] + d[i - x]) % M; }
      |                   ^~~
bootfall.cpp: In function 'void del(int)':
bootfall.cpp:32:31: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   32 | #define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
      |                               ^
bootfall.cpp:57:19: note: in expansion of macro 'FOR'
   57 | void del(int x) { FOR(i, x, NxN - 1) d[i] = (d[i] - d[i - x] + M) % M; }
      |                   ^~~
bootfall.cpp: In function 'int main()':
bootfall.cpp:32:31: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   32 | #define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
      |                               ^
bootfall.cpp:63:5: note: in expansion of macro 'FOR'
   63 |     FOR(i, 1, n) {
      |     ^~~
bootfall.cpp:32:31: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   32 | #define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
      |                               ^
bootfall.cpp:72:5: note: in expansion of macro 'FOR'
   72 |     FOR(i, 1, n) add(a[i]);
      |     ^~~
bootfall.cpp:32:31: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   32 | #define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
      |                               ^
bootfall.cpp:77:5: note: in expansion of macro 'FOR'
   77 |     FOR(i, 1, NxN - 1) c[i] = 1;
      |     ^~~
bootfall.cpp:32:31: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   32 | #define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
      |                               ^
bootfall.cpp:78:5: note: in expansion of macro 'FOR'
   78 |     FOR(i, 1, n) {
      |     ^~~
bootfall.cpp:32:31: warning: unnecessary parentheses in declaration of 'j' [-Wparentheses]
   32 | #define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
      |                               ^
bootfall.cpp:80:6: note: in expansion of macro 'FOR'
   80 |      FOR(j, 1, NxN - 1) {
      |      ^~~
bootfall.cpp:32:31: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   32 | #define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
      |                               ^
bootfall.cpp:91:5: note: in expansion of macro 'FOR'
   91 |     FOR(i, 1, NxN - 1)
      |     ^~~
bootfall.cpp:36:31: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   36 | #define EACH(i, x) for (auto &(i) : (x))
      |                               ^
bootfall.cpp:95:5: note: in expansion of macro 'EACH'
   95 |     EACH(i, ans) cout << i << ' ';
      |     ^~~~

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