light oj 1084 线性dp

#include <iostream>
#include <algorithm>
#include <cstring>
#include <cstdio>
#include <queue>
#define ll long long

using namespace std;
const int N = 1e5+1000;

int a[N],dp[N];

void solve()
{
    int n,k;
    scanf("%d %d",&n,&k);
    for(int i = 0; i < n; i++)
    {
        scanf("%d",&a[i]);
    }
    sort(a,a+n);
    memset(dp,0,sizeof(dp));
    for(int i = n-1; i >= 0; i--)
    {
        dp[i] = 0x3f3f3f;
        int j = upper_bound(a,a+n,a[i]+2*k)-a;
        if(j - i >= 3) dp[i] = min(dp[j]+1,dp[i]);
        if(j - i >= 4) dp[i] = min(dp[j-1]+1,dp[i]);
        if(j - i >= 5) dp[i] = min(dp[j-2]+1,dp[i]);
    }
    if(dp[0] == 0x3f3f3f)
        printf("-1\n");
    else
        printf("%d\n",dp[0]);
}

int main(void)
{
    int t,cnt = 0;
    scanf("%d",&t);

    while(t--)
    {
        printf("Case %d: ",++cnt);
        solve();
    }
    return 0;
}