Submission #726425

#	Time	Username	Problem	Language	Result	Execution time	Memory
726425		stevancv	Bootfall (IZhO17_bootfall)	C++14	100 / 100	981 ms	4520 KiB

bootfall

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define sp ' '
#define en '\n'
#define smin(a, b) a = min(a, b)
#define smax(a, b) a = max(a, b)
using namespace std;
const int N = 500 + 2;
const int mod = 1e9 + 7;
int a[N], cnt[N * N], dp92[N * N], dpc[N * N];
int Add(int a, int b) {
    a += b;
    while (a >= mod) a -= mod;
    while (a < 0) a += mod;
    return a;
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int n; cin >> n;
    int sum = 0;
    dp92[0] = 1;
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        sum += a[i];
        for (int j = sum; j >= a[i]; j--) {
            dp92[j] = Add(dp92[j], dp92[j - a[i]]);
        }
    }
    if (sum % 2 == 1 || dp92[sum / 2] == 0) {
        cout << 0 << en;
        return 0;
    }
    for (int i = 1; i <= n; i++) {
        for (int j = 0; j < a[i]; j++) dpc[j] = dp92[j];
        for (int j = a[i]; j <= sum; j++) dpc[j] = Add(dp92[j], -dpc[j - a[i]]);
        for (int j = 0; j <= sum; j++) {
            int x = 2 * j + a[i] - sum;
            if (dpc[j] > 0 && x > 0) cnt[x] += 1;
        }
    }
    vector<int> ans;
    for (int i = 1; i <= sum; i++) if (cnt[i] == n) ans.push_back(i);
    cout << ans.size() << en;
    for (int i : ans) cout << i << sp;
    cout << en;
    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