Codeforces Round #722 (Div. 2)B. Sifid and Strange Subsequen

Posted 2021-06-21 小哈里

problem

B. Sifid and Strange Subsequences
time limit per test1 second
memory limit per test256 megabytes
inputstandard input
outputstandard output
A sequence (b1,b2,…,bk) is called strange, if the absolute difference between any pair of its elements is greater than or equal to the maximum element in the sequence. Formally speaking, it’s strange if for every pair (i,j) with 1≤i<j≤k, we have |ai−aj|≥MAX, where MAX is the largest element of the sequence. In particular, any sequence of length at most 1 is strange.

For example, the sequences (−2021,−1,−1,−1) and (−1,0,1) are strange, but (3,0,1) is not, because |0−1|<3.

Sifid has an array a of n integers. Sifid likes everything big, so among all the strange subsequences of a, he wants to find the length of the longest one. Can you help him?

A sequence c is a subsequence of an array d if c can be obtained from d by deletion of several (possibly, zero or all) elements.

Input
The first line contains an integer t (1≤t≤104) — the number of test cases. The description of the test cases follows.

The first line of each test case contains an integer n (1≤n≤105) — the length of the array a.

The second line of each test case contains n integers a1,a2,…,an (−109≤ai≤109) — the elements of the array a.

It is guaranteed that the sum of n over all test cases doesn’t exceed 105.

Output
For each test case output a single integer — the length of the longest strange subsequence of a.

Example
inputCopy
6
4
-1 -2 0 0
7
-3 4 -2 0 -4 6 1
5
0 5 -3 2 -5
3
2 3 1
4
-3 0 2 0
6
-3 -2 -1 1 1 1
outputCopy
4
5
4
1
3
4
Note
In the first test case, one of the longest strange subsequences is (a1,a2,a3,a4)
In the second test case, one of the longest strange subsequences is (a1,a3,a4,a5,a7).

In the third test case, one of the longest strange subsequences is (a1,a3,a4,a5).

In the fourth test case, one of the longest strange subsequences is (a2).

In the fifth test case, one of the longest strange subsequences is (a1,a2,a4).

solution

#include<bits/stdc++.h>
using namespace std;
const int maxn = 1e5+10;
int a[maxn];
int main(){
	ios::sync_with_stdio(false);
	int T;  cin>>T;
	while(T--){
		int n;  cin>>n;
		int cnt = 0;
		for(int i = 1; i <= n; i++){
			cin>>a[i];
		}
		sort(a+1,a+n+1);
		int mi = 1e9+10;
		for(int i = 1; i <= n; i++){
			if(a[i]<=0){
				cnt++;
				if(i!=1)mi = min(mi,a[i]-a[i-1]);
			}else{
				if(a[i]<=mi)cnt++;
				break;
			}
		}
		if(cnt==0)cnt = 1;
		cout<<cnt<<"\\n";
	}
	return 0;
}