hdu2466-Shell Pyramid

先预处理一下层和行所对应的数，然后二分三个答案，注意细节

 

#include<cstdio>

#define inf 0x3f3f3f3f

const int maxn=;

typedef __int64 LL;

using namespace std;

int i;

LL n,s,ans1,ans2,ans3;

LL sum[maxn+];

LL a[maxn+];

void solve(){
  int flag=;
  LL lb=,ub=maxn,mid=(lb+ub)>>;
  while(ub-lb>){
        mid=(lb+ub)>>;
        if(s>a[mid]) lb=mid;
        else if(s<a[mid]) ub=mid;
        else if(s==a[mid]) {
        flag=;
        break;
        }
  }
  if(s<=a[mid]&&s>=a[mid-]&&flag) ans1=mid;
  else if(s<=a[lb]&&s>=a[lb-]) ans1=lb;
  else if(s<=a[ub]&&s>=a[ub-]) ans1=ub;
  s-=(a[ans1-]);
  //printf("%I64d\n",s);
  //printf("%I64d\n",ans1);
  flag=;
  lb=,ub=ans1,mid=(lb+mid)>>;
  while(ub-lb>){
        mid=(lb+ub)>>;
       // printf("%d %d\n",mid,sum[3]);
        if(s>sum[mid])
        lb=mid;
        else if(s<sum[mid])
        ub=mid;
        else if(s==sum[mid]){
                flag=;
                break;
        }
  }
  //printf("%I64d %I64d %I64d %I64d\n",sum[lb],sum[lb-1],s,lb);
  if(s<=sum[mid]&&s>=sum[mid-]&&flag){
       // printf("1 %I64d %I64d %I64d %I64d\n",sum[mid],sum[mid-1],s,mid);
        ans2=mid;
  }
  else if(s<=sum[lb]&&s>=sum[lb-]){
       // printf("2 %I64d %I64d %I64d %I64d\n",sum[lb],sum[lb-1],s,lb);
        ans2=lb;
  }
  else if(s<=sum[ub]&&s>=sum[ub-]){
        //printf("3 %I64d %I64d %I64d %I64d\n",sum[ub],sum[ub-1],s,ub);
        ans2=ub;
  }
  flag=;
  lb=,ub=ans2,mid=(lb+ub)>>;
  //printf("%d\n",ans2);
  while(ub-lb>){
        mid=(lb+ub)>>;
        if(s>sum[ans2-]+mid)  lb=mid;
        else if(s<sum[ans2-]+mid) ub=mid;
        else if(s==mid+sum[ans2-]) {
                flag=;
                break;
        }
  }
  if(s==mid+sum[ans2-]&&flag) ans3=mid;
  else if(s==lb+sum[ans2-]) ans3=lb;
  else if(s==ub+sum[ans2-]) ans3=ub;
  printf("%I64d %I64d %I64d\n",ans1,ans2,ans3);
}

int main()
{
    for(int i=;i<=maxn;i++)
        sum[i]=sum[i-]+i;
    for(int i=;i<=maxn;i++)
        a[i]=sum[i]+a[i-];
    scanf("%I64d",&n);
    while(n--){
        scanf("%I64d",&s);
        solve();
    }
    return ;
}