Given a sequence of positive integers and another positive integer p. The sequence is said to be a "perfect sequence" if M <= m * p where M and m are the maximum and minimum numbers in the sequence, respectively.
Now given a sequence and a parameter p, you are supposed to find from the sequence as many numbers as possible to form a perfect subsequence.
Input Specification:
Each input file contains one test case. For each case, the first line contains two positive integers N and p, where N (<= 105) is the number of integers in the sequence, and p (<= 109) is the parameter. In the second line there are N positive integers, each is no greater than 109.
Output Specification:
For each test case, print in one line the maximum number of integers that can be chosen to form a perfect subsequence.
Sample Input:
10 8 2 3 20 4 5 1 6 7 8 9
Sample Output:
8
#include<cstdio> #include<algorithm> using namespace std; int n,p,a[100010]; int binarySearch(int i, long long x){ if(a[n - 1] <= x) return n; int l = i + 1, r = n - 1; while(l < r){ int mid = (r + l) / 2; if(a[mid] <= x){ l = mid + 1; }else{ r = mid; } } return l; } int main(){ scanf("%d%d",&n,&p); for(int i = 0; i < n; i++){ scanf("%d",&a[i]); } sort(a,a+n); int ans = 1; for(int i = 0; i < n; i++){ int j = binarySearch(i,(long long)a[i]*p); ans = max(ans, j - i); } printf("%d\n",ans); return 0; }