Submission #36161

#	Time	Username	Problem	Language	Result	Execution time	Memory
36161		cheater2k	Bootfall (IZhO17_bootfall)	C++14	100 / 100	496 ms	5164 KiB

bootfall

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

const int N = 505;
const int MAX = N * N;

int n, a[N];
int sum;
int dp[MAX]; // knapsack
int tmp[MAX]; // for solve(pos)
int check[MAX];

void solve(int pos) {
	for (int i = 0; i <= sum; ++i) tmp[i] = dp[i];
	for (int i = 0; i <= sum; ++i) {
		// we do not use a[pos]
		if (i >= a[pos]) {
			tmp[i] -= tmp[i - a[pos]];
		}
	}
	for (int i = 0; i <= sum; ++i) {
		if (tmp[i] != 0 && a[pos] + 2 * i - sum >= 0) 
			check[a[pos] + 2 * i - sum]++;
	}
}

int main() {
	ios_base::sync_with_stdio(false); cin.tie(0);
	cin >> n;
	for (int i = 1; i <= n; ++i) cin >> a[i];

	// prepare KNAPSACK
	dp[0] = 1;
	for (int i = 1; i <= n; ++i) {
		sum += a[i];
		for (int j = sum; j >= a[i]; --j) {
			dp[j] += dp[j - a[i]];
		}
	}

	if ((sum & 1) || (dp[sum / 2] == 0)) return printf("0\n"), 0; // invalid

	for (int i = 1; i <= n; ++i) solve(i);

	int cnt = 0;
	for (int i = 1; i <= sum; ++i) if (check[i] == n) ++cnt;
	printf("%d\n", cnt);
	for (int i = 1; i <= sum; ++i) if (check[i] == n) printf("%d ", i); printf("\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