K 番目のビットが設定されている範囲内の配列要素の数をクエリするために C++ で記述されたコード

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