Cod sursa(job #2075884)
Utilizator | iulius alexandru iulius510 | Data | 25 noiembrie 2017 19:46:27 |
---|---|---|---|
Problema | Fractii | Scor | 90 |
Compilator | c | Status | done |
Runda | Arhiva de probleme | Marime | 0.48 kb |
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
long long S;
int main()
{
FILE *f,*g;
f=fopen("fractii.in","r");
g=fopen("fractii.out","w");
long long N;
long long i,e[1000000],j;
fscanf(f,"%lld",&N);
for(i=1;i<=N;i++)
e[i]=i-1;
for(i=1;i<=N;i++)
for(j=2*i;j<=N;j+=i)
{
e[j]=e[j]-e[i];
}
for(i=1;i<=N;i++)
S+=e[i];
fprintf(g,"%lld",2*S+1);
return 0;
}