Submission #173463

#	Time	Username	Problem	Language	Result	Execution time	Memory
173463		srvlt	Bootfall (IZhO17_bootfall)	C++14	28 / 100	154 ms	760 KiB

bootfall

//#pragma GCC optimize("Ofast")
//#pragma GCC target("avx,avx2,fma")
#include <bits/stdc++.h>

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ordered_set tree <pair <int, int>, null_type, less <pair <int, int> >, rb_tree_tag, tree_order_statistics_node_update>
using namespace __gnu_pbds;

#define ll long long
#define db double
#define pb push_back
#define ppb pop_back
#define fi first
#define se second
#define mp make_pair
#define size(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()
#define low_b lower_bound

#define endl "\n"
//#define int long long

using namespace std;

void dout() {
    cerr << endl;
}
template <typename Head, typename... Tail>
void dout(Head H, Tail... T) {
    cerr << H << ' ';
    dout(T...);
}

//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
typedef pair <int, int> pii;

const int N = 102, M = 10001;
int n, a[N], total;
bitset <M> p[N], s[N], res, ans, tmp;

void dbg(bitset <M> & b) {
    for (int i = 0; i < M; i++) {
        cout << b[i];
    }
    cout << endl;
}

void solve(int tc) {
    // check for (int i = 0; i < n; j++)
    cin >> n;
    p[0][0] = 1;
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        total += a[i];
        p[i] = p[i - 1];
        p[i] |= (p[i] << a[i]);
    }
    if ((total & 1) || !p[n][total >> 1]) {
        cout << 0;
        return;
    }
    s[n + 1][0] = 1;
    for (int i = n; i >= 1; i--) {
        s[i] = s[i + 1];
        s[i] |= (s[i] << a[i]);
    }
    int w;
    ans.set();
    for (int i = 1; i <= n; i++) {
        tmp = s[i + 1];
        for (int j = 1; j < M; j++) {
            if (p[i - 1][j]) {
                tmp |= (s[i + 1] << j);
            }
        }
        res.reset();
        w = total - a[i];
        for (int j = (w & 1); j <= w; j += 2) {
            if (tmp[w + j >> 1] || tmp[w - j >> 1]) {
                res[j] = 1;
            }
        }
        ans &= res;
    }
    cout << ans.count() << endl;
    for (int i = 0; i < M; i++) {
        if (ans[i]) {
            cout << i << " ";
        }
    }
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
//    freopen("input.txt", "r", stdin);
//    freopen("output.txt", "w", stdout);
    int tc = 1;
//    cin >> tc;
    for (int i = 0; i < tc; i++) {
        solve(i);
//        cleanup();
    }
}

Compilation message (stderr)

bootfall.cpp: In function 'void solve(int)':
bootfall.cpp:80:23: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
             if (tmp[w + j >> 1] || tmp[w - j >> 1]) {
                     ~~^~~
bootfall.cpp:80:42: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
             if (tmp[w + j >> 1] || tmp[w - j >> 1]) {
                                        ~~^~~

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