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=2000100;

typedef __int64 LL;

using namespace std;

int i;

LL n,s,ans1,ans2,ans3;

LL sum[maxn+10];

LL a[maxn+10];

void solve(){
  int flag=0;
  LL lb=0,ub=maxn,mid=(lb+ub)>>1;
  while(ub-lb>1){
        mid=(lb+ub)>>1;
        if(s>a[mid]) lb=mid;
        else if(s<a[mid]) ub=mid;
        else if(s==a[mid]) {
        flag=1;
        break;
        }
  }
  if(s<=a[mid]&&s>=a[mid-1]&&flag) ans1=mid;
  else if(s<=a[lb]&&s>=a[lb-1]) ans1=lb;
  else if(s<=a[ub]&&s>=a[ub-1]) ans1=ub;
  s-=(a[ans1-1]);
  //printf("%I64d\n",s);
  //printf("%I64d\n",ans1);
  flag=0;
  lb=1,ub=ans1,mid=(lb+mid)>>1;
  while(ub-lb>1){
        mid=(lb+ub)>>1;
       // 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=1;
                break;
        }
  }
  //printf("%I64d %I64d %I64d %I64d\n",sum[lb],sum[lb-1],s,lb);
  if(s<=sum[mid]&&s>=sum[mid-1]&&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-1]){
       // printf("2 %I64d %I64d %I64d %I64d\n",sum[lb],sum[lb-1],s,lb);
        ans2=lb;
  }
  else if(s<=sum[ub]&&s>=sum[ub-1]){
        //printf("3 %I64d %I64d %I64d %I64d\n",sum[ub],sum[ub-1],s,ub);
        ans2=ub;
  }
  flag=0;
  lb=1,ub=ans2,mid=(lb+ub)>>1;
  //printf("%d\n",ans2);
  while(ub-lb>1){
        mid=(lb+ub)>>1;
        if(s>sum[ans2-1]+mid)  lb=mid;
        else if(s<sum[ans2-1]+mid) ub=mid;
        else if(s==mid+sum[ans2-1]) {
                flag=1;
                break;
        }
  }
  if(s==mid+sum[ans2-1]&&flag) ans3=mid;
  else if(s==lb+sum[ans2-1]) ans3=lb;
  else if(s==ub+sum[ans2-1]) ans3=ub;
  printf("%I64d %I64d %I64d\n",ans1,ans2,ans3);
}

int main()
{
    for(int i=1;i<=maxn;i++)
        sum[i]=sum[i-1]+i;
    for(int i=1;i<=maxn;i++)
        a[i]=sum[i]+a[i-1];
    scanf("%I64d",&n);
    while(n--){
        scanf("%I64d",&s);
        solve();
    }
    return 0;
}