UVA 1372 - Log Jumping（推理）

#include <stdio.h>
#include <string.h>
#include <algorithm>
using namespace std;
#define max(a,b) ((a)>(b)?(a):(b))
#define INF 0x3f3f3f3f
const int N = 5005;
int t, n, k, i, start[N];

bool check(int s, int e) {
	return e - s <= k;
}

int main() {
	scanf("%d", &t);
	while (t--) {
		int ans = 0;
		scanf("%d%d", &n, &k);
		for (i = 0; i< n; i++)
			scanf("%d", &start[i]);
		sort(start, start + n);
		i = 0;
		while (i < n) {
			int sum = 1;
			while (i < n - 1 && ((sum == 1 && check(start[i], start[i + 1])) || 
				(check(start[i], start[i + 1]) && check(start[i - 1], start[i + 1]))))
				sum++, i++;
			if (!check(start[i], start[i + 1]) || i == n - 1) i++;
			ans = max(ans, sum);
		}
		printf("%d\n", ans);
	}
	return 0;
}