HDU5806 NanoApe Loves Sequence Ⅱ (BestCoder Round #86 C)二分

#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
using namespace std;
typedef long long LL;
const int N = 2e5+5;
int T,n,m,k,a
,sum
;
int main(){
scanf("%d",&T);
while(T--){
scanf("%d%d%d",&n,&m,&k);
for(int i=1;i<=n;++i){
scanf("%d",&a[i]);
if(a[i]>=m)a[i]=1;
else a[i]=0;
}
for(int i=1;i<=n;++i)sum[i]=sum[i-1]+a[i];
LL ret=0;
for(int i=1;i<=n;++i){
if(n-i+1<k)break;
if(sum
-sum[i-1]<k)break;
int l=i+k-1,r=n;
while(l<r){
int mid=(l+r)>>1;
if(sum[mid]-sum[i-1]>=k)r=mid;
else l=mid+1;
}
int tmp=(l+r)>>1;
ret+=(n-tmp+1);
}
printf("%I64d\n",ret);
}
return 0;
}