Submission #697027

#	Time	Username	Problem	Language	Result	Execution time	Memory
697027		allllekssssa	Bootfall (IZhO17_bootfall)	C++14	100 / 100	535 ms	10348 KiB

bootfall

#include<bits/stdc++.h>
 
using namespace std;
 
const int maxN = 500 + 5;
const int bsSize = (maxN * maxN + 10) / 2;
int n;
int a[maxN];
int cnt[maxN];
bitset<bsSize> dp[2][maxN], pre;
 
int main() {
 
	cin >> n;
    
	int sum = 0;
    int gc = 0;
	for (int i = 1; i<=n; i++) {
	    cin >> a[i];
		gc = __gcd(a[i], gc);
	}
 
	for (int i = 1; i<=n; i++) {
		a[i]/=gc;
		if ((a[i] & 1) == 0) {
			printf("0\n");
			return 0;
		}
		if (cnt[a[i]] == 0) cnt[a[i]] = i;
		sum+=a[i];
	}
 
	if (sum & 1) {
    	printf("0\n");
    	return 0;    	
    }
    
 
	for (int i = 1; i <= n + 1; i++) {
		dp[0][i].set(0);
	}
 
	for (int i = 1; i<=n; i++) {
		bool updated = false;
		for (int j = 1; j <= n + 1; j++) {
			if (j<= n && cnt[a[j]] != j) continue;
			
			if (i == j) {
				dp[i&1][j] = dp[(i&1) ^ 1][j];
			} else {
					if (updated) {
						dp[i&1][j] = pre;
					} else {
					dp[i&1][j] = dp[(i&1) ^ 1][j] | (dp[(i&1) ^ 1][j] << a[i]);
					if (i < j && !updated) {
			   			pre = dp[i&1][j];
			   			updated = true;
			   	    }
			   	}
			 }
		}
	}
 
 
	if (dp[n&1][n + 1][sum/2] == 0) {
		printf("0\n");
		return 0;
	}
 
    vector<int> ans;
 
	for (int i = 1; i <= sum; i+=2) {
		bool ok = true;
         
        for (int j = 1; j<= n; j++) {
        	if (cnt[a[j]] != j) continue;
        	int totSum = sum  - a[j] + i;
        	if (totSum % 2 == 1) ok = false;
        	int val = sum - totSum/2 - a[j];
            if (val  < 0) ok = false;
        	if (ok && dp[n&1][j][val] == 0) ok = false;
        }
 
		if (ok) ans.push_back(i);
	}
 
	cout << ans.size() << endl;
 
	for (int i:ans) {
		cout << i * gc << " ";
	}
 
	cout << endl;
}

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