Submission #706867

#	Time	Username	Problem	Language	Result	Execution time	Memory
706867		Shreyan_Paliwal	Bootfall (IZhO17_bootfall)	C++17	100 / 100	350 ms	3916 KiB

bootfall

#include <bits/stdc++.h>
using namespace std;

const int maxn = 500;
const int maxk = maxn * maxn;

int n;
int dp[maxk + 1];
int dp2[maxk + 1];
int weights[maxn];

int main() {
    // freopen("main.in", "r", stdin);

    cin >> n;
    for (int i = 0; i < n; i++) cin >> weights[i];

    // calc knapsack
    dp[0] = 1;
    for (int i = 0; i < n; i++) { // for weight
        for (int j = maxk; j >= weights[i]; j--) {
            dp[j] += dp[j - weights[i]];
        }
    }

    int sm = accumulate(weights, weights + n, 0);
    if (sm & 1 || !dp[sm / 2]) {
        cout << 0 << endl;
        return 0;
    }

    int works[maxk + 1];
    fill(works, works + maxk + 1, 1);
    // for each weight
    for (int i = 0; i < n; i++) {
        // remove weight
        for (int j = 0; j <= maxk; j++) dp2[j] = dp[j];
        for (int j = weights[i]; j <= maxk; j++) dp2[j] -= dp2[j - weights[i]];


        // update works array
        for (int j = 1; j <= maxk; j++) {
            int SM = sm - weights[i] + j;
            if (SM & 1 || !dp2[SM / 2])
                works[j] = false;
        }
    }

    int ans = accumulate(works + 1, works + maxk + 1, 0);
    cout << ans << endl;
    for (int i = 1; i <= maxk; i++)
        if (works[i]) cout << i << ' ';
    cout << endl;

    return 0;
}

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