【板刷算进计划】起床困难综合征 / uoj 2【位运算】【贪心】

#include 

using namespace std;

int n, m;
const int N = 1e5 + 10;
int a[N], opt[N];

bool calc(bool x, int y)
{
  for (int i = 0; i < n; i ++)
    if (opt[i] == 1)
      x |= a[i] >> y & 1;
    else if (opt[i] == 2)
      x &= a[i] >> y & 1;
    else
      x ^= a[i] >> y & 1;
  return x;
}

signed main()
{
  cin >> n >> m;
  for (int i = 0; i < n; i ++)
  {
    string s;
    cin >> s;
    cin >> a[i];
    if (s == "OR")
      opt[i] = 1;
    else if (s == "AND")
      opt[i] = 2;
    else
      opt[i] = 3;
  }
  int ans = 0;
  for (int i = 29; ~i; i --)
    if ((1 << i) <= m)
    {
      bool _1 = calc(0, i), _2 = calc(1, i);
      if (_1 >= _2)
        ans |= _1 << i;
      else
        ans |= _2 << i, m -= 1 << i;
    }
    else
      ans |= calc(0, i) << i;
  cout << ans << '\n';
  return 0;
}

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