Submission #342626

#	Time	Username	Problem	Language	Result	Execution time	Memory
342626		Sorting	Bootfall (IZhO17_bootfall)	C++17	100 / 100	131 ms	18988 KiB

bootfall

#include <bits/stdc++.h>

using namespace std;

const int N = 500 + 3;

int n, a[N], sum;
bitset<N * N> dp[N];
int is_ans[N * N];
vector<int> ans;

void dnc(int l, int r, const bitset<N * N> &b){
    if(l == r) dp[l] = b;
    else{
        int mid = (l + r) >> 1;
        bitset<N * N> new_b;

        new_b = b;
        for(int i = l; i <= mid; ++i)
            new_b |= new_b << a[i];

        dnc(mid + 1, r, new_b);

        new_b = b;
        for(int i = mid + 1; i <= r; ++i)
            new_b |= new_b << a[i];
    
        dnc(l, mid, new_b);
    }
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(NULL);

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

    if(sum & 1){
        cout << "0\n";
        return 0;
    }

    bitset<N * N> curr;
    curr[0] = 1;
    dnc(0, n, curr);

    if(!dp[n][(sum >> 1)]){
        cout << "0\n";
        return 0;
    }

    for(int i = 0; i < n; ++i){
        for(int j = (sum - a[i]) & 1; j <= sum; j += 2){
            int new_sum = sum - a[i] + j;
            if(dp[i][(new_sum >> 1)])
                is_ans[j]++;
        }
    }

    for(int i = 0; i <= sum; ++i)
        if(is_ans[i] == n)
            ans.push_back(i);

    cout << ans.size() << "\n";
    for(int x: ans)
        cout << x << " ";
    cout << "\n";
}

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