Cod sursa(job #67507)

Utilizator razvi9Jurca Razvan razvi9 Data 25 iunie 2007 10:43:16
Problema P-sir Scor 0
Compilator cpp Status done
Runda preONI 2007, Runda Finala, Clasele 11-12 Marime 0.5 kb
#include<stdio.h>

int a[2001],i,j,k,n;
unsigned long nr[2001],N;

int sgn(int x,int y)
{if(x<y) return -1;
 if(x==y) return 0;
 return 1;}

int main()
{freopen("psir.in","r",stdin);
 freopen("psir.out","w",stdout);
 scanf("%d",&n);
 for(i=1;i<=n;i++)
  scanf("%d",&a[i]);
 for(i=1;i<n-1;i++)
  for(j=i+1;j<n;j++)
   for(k=j+1;k<=n;k++)
    if((sgn(a[k],a[i])*sgn(a[k],a[j])) < 0)  nr[k]+=nr[i]+1;
 N=n*(n-1)/2;
 for(i=1;i<=n;i++)
  N=N+nr[i];
 printf("%d",N);
 fclose(stdout);
 return 0;}