Codeforces Round #392 (Div. 2), problem: (F) Geometrical Progression Solution in C/C++

#include<stdio.h>
#include<stdlib.h>
#define N 10000001
#define SN 3163
typedef long long unsigned llu;
typedef unsigned u;
int F(const void*x,const void*y)
{
if(*(llu*)x>*(llu*)y)return 1;
if(*(llu*)y>*(llu*)x)return-1;
return 0;
}
u D[N],Ga[N],Gi[N];llu *G[N];
int main()
{
u a,b,c,i,j,k,n,x,y,lo,hi,mi;llu e;llu r=0;
for(i=0;++i<SN;)for(k=i*i,j=0;(j+=k)<N;)D[j]=i;
scanf(“%u%u%u”,&n,&x,&y);
if(n<3)
{
r=y-x+1;
if(n==0)r=1;
if(n==2)r=r*(r-1);
printf(“%I64u\n”,r);
return 0;
}
for(a=y+1;a–>x;)
{
for(i=0;++i;)
{
if((b=a/D[a]*(D[a]+i))>y)break;
if((c=b/D[a]*(D[a]+i))>y)break;
if(n==3){++r;continue;}
if((e=c*(llu)(D[a]+i))%D[a]>0||e/D[a]>y)continue;
j=c/(b/D[b]);
lo=0;hi=Gi[b];
while((mi=(lo+hi)>>1)>lo)
{
if((G[b][mi]>>32)>j)hi=mi;
else lo=mi;
}
if(!hi||(G[b][lo]>>32)!=j)k=4;
else k=1+(G[b][lo]&-1u);
if(Gi[a]==Ga[a])
{
if(!Ga[a])G[a]=(llu*)calloc(Ga[a]=1,sizeof(llu));
else G[a]=(llu*)realloc(G[a],(Ga[a]<<=1)*sizeof(llu));
}
G[a][Gi[a]++]=(((llu)(D[a]+i))<<32)|((llu)k);
if(k>=n)++r;
}
if(Gi[a])qsort(G[a],Gi[a],sizeof(llu),F);
}
printf(“%I64u\n”,r<<1);
return 0;
}

There is a cloud...

Imagine a vast, shimmering cloud floating through the cold...

China’s three telecom giants...

China’s telecommunications landscape is undergoing a monumental paradigm shift....

Why Everyone is Obsessed with the Powerful Electric Air Duster

Are you tired of dealing with everyday frustrations that slow down your routine? We've all been...

There is a cloud of alcohol drifting through the constellation Aquila that is 1,000 times the diameter of our solar system and contains enough...

Imagine a vast, shimmering cloud floating through the cold expanse of deep space, holding enough alcohol to supply every tavern on Earth for eternity....

Why Everyone is Obsessed with the Wireless Karaoke Microphone

Are you tired of dealing with everyday frustrations that slow down your routine? We've all been...

Why Everyone is Obsessed with the Sunset Projection LED Lamp

Are you tired of dealing with everyday frustrations that slow down your routine? We've all been...

China’s three telecom giants race into the AI token economy

China’s telecommunications landscape is undergoing a monumental paradigm shift. The nation's three state-owned telecom giants—China Mobile, China Telecom, and China Unicom—are aggressively moving beyond...

Why Everyone is Obsessed with the USB Rechargeable Lighter

Are you tired of dealing with everyday frustrations that slow down your routine? We've all been...

Why Everyone is Obsessed with the AeroPress Coffee Maker

Are you tired of dealing with everyday frustrations that slow down your routine? We've all been...

Fangzhou Ranked among 2025 Guangzhou AI Innovation “Most Promising Enterprises” for AI‑Powered Chronic Disease Services

In a significant milestone for the digital healthcare sector, Fangzhou has been officially ranked among the 2025 Guangzhou AI Innovation 'Most Promising Enterprises' list....

Why Everyone is Obsessed with the Universal Car Cleaning Gel

Are you tired of dealing with everyday frustrations that slow down your routine? We've all been...