Submission #148083

#	Time	Username	Problem	Language	Result	Execution time	Memory
148083		WhipppedCream	Ice Hockey World Championship (CEOI15_bobek)	C++17	100 / 100	547 ms	8784 KiB

bobek

#include <bits/stdc++.h>
#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")
using namespace std;
#define X first
#define Y second
#define pb push_back
typedef pair<int, int> ii;
typedef long long ll;
 
int n;
ll S;
 
const int maxn = 45;
ll arr[maxn];
 
vector< ll > half;
 
ll ways;
 
int main()
{
	scanf("%d %lld", &n, &S);
	for(int i = 1; i<= n; i++) scanf("%lld", &arr[i]);
	int m = n/2;
	for(int bit = 0; bit< (1<<m); bit++)
	{
		ll loc = 0;
		for(int i = 0; i< m; i++)
		{
			if((1<<i) & bit) loc += arr[i+1];
		}
		half.pb(loc);
	}
	sort(half.begin(), half.end());
	m = n-n/2;
	for(int bit = 0; bit< (1<<m); bit++)
	{
		ll loc = 0;
		for(int i = 0; i< m; i++)
		{
			if((1<<i)&bit) loc += arr[n/2+1+i];
		}
		ways += upper_bound(half.begin(), half.end(), S-loc)-half.begin();
	}
	printf("%lld\n", ways);
}

Compilation message (stderr)

bobek.cpp: In function 'int main()':
bobek.cpp:23:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %lld", &n, &S);
  ~~~~~^~~~~~~~~~~~~~~~~~~
bobek.cpp:24:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i = 1; i<= n; i++) scanf("%lld", &arr[i]);
                             ~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10