K번째 비트가 설정된 범위의 배열 요소 수를 쿼리하기 위해 C++로 작성된 코드

Input : arr[] = { 4, 5, 7, 2 }
Query 1: L = 2, R = 4, K = 4
Query 2: L = 3, R = 5, K = 1
Output :
   0
   1

#include<bits/stdc++.h>
using namespace std;
#define MAX_BITS 32
bool Kset(int n, int k) { // to check if kth bit is set
   if (n & (1 << (k - 1)))
   return true;
   return false;
}
int query(int L, int R, int K, int arr[]) {
   int count = 0; // counter to keep count of number present in the range
   for (int i = L; i <= R; i++) { // traversing the range
      if (Kset(arr[i], K)) {
         count++;
      }
   }
   return count;
}
int main() {
   int arr[] = { 4, 5, 7, 2 }; // given array
   int n = sizeof(arr) / sizeof(arr[0]); // size of our array
   int queries[][3] = { // given L, R and k
      { 2, 4, 4 },
      { 3, 5, 1 }
   };
   int q = sizeof(queries) / sizeof(queries[0]); // number of queries

   for (int i = 0; i < q; i++) {
      int L = queries[i][0] - 1;
      int R = queries[i][1] - 1;
      int K = queries[i][2];

      cout << query(L, R, K, arr) << "\n";
   }
   return 0;
}

0
1

#include<bits/stdc++.h>
using namespace std;
#define bits 32 // number of bits

int P[100000][bits+1];

bool Kset(int n, int k) {
   if (n & (1 << (k - 1)))
      return true;
   return false;
}
void prefixArray(int n, int arr[]) { // building the prefix array
   for (int i = 0; i <= bits; i++) {
      P[0][i] = 0; // setting every bits initial count = 0
   }
   for (int i = 0; i < n; i++) {
      for (int j = 1; j <= bits; j++) {
         bool flag = Kset(arr[i], j);
         if (i) // we add previous count to the latest count(0)
            P[i][j] = P[i - 1][j];
         if (flag) { // if jth bit is set so we increase the count
            P[i][j]++;
         }
      }
   }
}
int query(int L, int R, int K) {
   if (L) // if L not equal to 0 then we return the prefix at R subtracted with prefix at L-1
      return P[R][K] - P[L - 1][K];
   else
      return P[R][K];
}
int main() {
   int arr[] = { 8, 9, 1, 3 }; // given array
   int n = sizeof(arr) / sizeof(arr[0]); // size of given array
   int queries[][3] = {
      { 1, 3, 4 },
      { 2, 4, 1 }
   };
   prefixArray(n, arr); // calling the function to create prefix array
   int q = sizeof(queries) / sizeof(queries[0]); // number of queries

   for (int i = 0; i < q; i++) {
      int L = queries[i][0] - 1;
      int R = queries[i][1] - 1;
      int K = queries[i][2];
      cout << query(L, R, K) << "\n";
   }
   return 0;
}

2
3