[codeground] 버스타기 : https://www.codeground.org/practice/practiceProblemViewNew

버스타기.cc

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int Answer;

int main(int argc, char** argv)
{
	int T, test_case;

	cin >> T;
	for (test_case = 0; test_case < T; test_case++)
	{
		int N, K;
		cin >> N >> K;
		vector<int> arr(N);
		for (int i = 0; i < N; i++) {
			cin >> arr[i];
		}
		sort(arr.begin(), arr.end());
		Answer = 0;
		int L = 0;
		for (int R = 0; R < N; R++) {
			// except I can go with arr[R]
			while (L < R && arr[R] - arr[L] > K) {
				L++;
			}
			Answer = max(Answer, R - L + 1);
		}
		
		cout << "Case #" << test_case + 1 << endl;
		cout << Answer << endl;
	}

	return 0;
}