Submission #975258

#	Time	Username	Problem	Language	Result	Execution time	Memory
975258		duckindog	Ice Hockey World Championship (CEOI15_bobek)	C++17	100 / 100	238 ms	22496 KiB

bobek

#include <bits/stdc++.h>

using namespace std;

const int N = 40 + 10;
int n;
long long m;
long long a[N], b[N];

int32_t main() { 
  cin.tie(0)->sync_with_stdio(0);

  cin >> n >> m;
  vector<long long> first = {0}, second = {0};
  {    
    int x = (n + 1 >> 1), y = n - x;
    for (int i = 1; i <= x; ++i) cin >> a[i];
    for (int i = 1; i <= y; ++i) cin >> b[i];

    for (int bit = 1; bit < (1 << x); ++bit) { 
      long long sum = 0;
      for (int j = 1; j <= x; ++j) sum += (bit >> j - 1 & 1) * a[j];
      if (sum <= m) first.push_back(sum);
    }

    for (int bit = 1; bit < (1 << y); ++bit) { 
      long long sum = 0;
      for (int j = 1; j <= y; ++j) sum += (bit >> j - 1 & 1) * b[j];
      if (sum <= m) second.push_back(sum);
    }
  }
  sort(first.begin(), first.end());
  sort(second.begin(), second.end());

  long long answer = 0;
  for (const auto& x : first) answer += upper_bound(second.begin(), second.end(), m - x) - second.begin();

  cout << answer << "\n";
}

Compilation message (stderr)

bobek.cpp: In function 'int32_t main()':
bobek.cpp:16:16: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   16 |     int x = (n + 1 >> 1), y = n - x;
      |              ~~^~~
bobek.cpp:22:53: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
   22 |       for (int j = 1; j <= x; ++j) sum += (bit >> j - 1 & 1) * a[j];
      |                                                   ~~^~~
bobek.cpp:28:53: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
   28 |       for (int j = 1; j <= y; ++j) sum += (bit >> j - 1 & 1) * b[j];
      |                                                   ~~^~~

• 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