Submission #229888

#	Time	Username	Problem	Language	Result	Execution time	Memory
229888		pedroslrey	Bootfall (IZhO17_bootfall)	C++14	100 / 100	935 ms	3568 KiB

bootfall

#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")

#include <bits/stdc++.h>

using namespace std;

using pii = pair<int, int>;
using lli = long long int;

#define debug(args...) fprintf(stderr, args)
#define pb push_back
#define fi first
#define se second
#define all(xs) xs.begin(), xs.end()

const int INF = 1e9;

int dp[510*510];
int xs[510];
int marc[510*510];

inline void add(int i, int s) {
	for (int k = s; k >= 0; --k) {
		lli tmp = 1LL*dp[k + xs[i]] + dp[k];
		dp[k + xs[i]] = tmp%INF;
	}
}

inline void sub(int i, int s) {
	for (int k = 0; k <= s; ++k) {
		lli tmp = 1LL*dp[k + xs[i]] - dp[k];
		dp[k + xs[i]] = tmp%INF;
	}
}

void init_dp(int n, int s) {
	dp[0] = 1;
	
	for (int i = 1; i <= n; ++i)
		add(i, s);
}

void solve(int n) {
	int s = 0;
	for (int i = 1; i <= n; ++i) 
		s += xs[i];

	init_dp(n, s);
	if (dp[s/2] == 0 || s%2 == 1) {
		printf("0\n");
		return;
	}

	for (int i = 1; i <= n; ++i) {
		sub(i, s);
		for (int k = 1; k <= s; ++k) {
			if ((s - xs[i] + k)%2 == 1) marc[k] = 0;
			if (s - xs[i] - k < 0) continue;
			else if (dp[(s - xs[i] - k)/2]) ++marc[k];
		} 
		add(i, s);
	}

	vector<int> ans;
	for (int k = 1; k <= s; ++k) 
		if (marc[k] == n) ans.pb(k);

	printf("%d\n", (int) ans.size());
	for (int a: ans) 
		printf("%d ", a);
	printf("\n");
}

int main() {
	int n;
	scanf("%d", &n);

	for (int i = 1; i <= n; ++i)
		scanf("%d", &xs[i]);

	solve(n);
}

Compilation message (stderr)

bootfall.cpp:2:0: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
 #pragma GCC optimization ("O3")
 
bootfall.cpp:3:0: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
 #pragma GCC optimization ("unroll-loops")
 
bootfall.cpp: In function 'int main()':
bootfall.cpp:78:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ~~~~~^~~~~~~~~~
bootfall.cpp:81:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &xs[i]);
   ~~~~~^~~~~~~~~~~~~~

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