Saruman's Army

#include <cstdio>
#include <iostream>
#include <algorithm>

using namespace std;

#define MAX_N 2000

int N,R;
int X[MAX_N];

void solve()
{
    sort(X,X+N);
    int i=0,ans=0;
    while(i<N)
    {
        int s=X[i++];
        while(i<N&&X[i]<=s+R)
            i++;
        int p=X[i-1];
        while(i<N&&X[i]<=p+R)
            i++;
        ans++;
    }
    printf("%d
",ans);
}

int main()
{
    printf("N R:
");
    scanf("%d %d",&N,&R);

    printf("X[%d]:
",N);
    for(int i=0;i<N;i++)
    {
        scanf("%d",&X[i]);
    }

    solve();
    return 0;
}