Cod sursa(job #544701)

Utilizator mening12001Andrei Geogescu mening12001 Data 1 martie 2011 22:49:44
Problema 12-Perm Scor 0
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.42 kb
#include<iostream.h>
#include<fstream.h>
long long x[100000],n,z=0;
ifstream f("12perm.in");
ofstream h("12perm.out");
int valid(int k)
{int i;
for(i=1;i<k;i++)
	if(x[k]==x[i])
		return 0;
	if(x[k-1]-x[k]>=3||x[k-1]-x[k]<=-3)
		return 0;
	return 1;}
void back(int k)
{int i;
for(i=1;i<=n;i++)
{x[k]=i;
if(valid(k)==1)
	if(k==n)
	z++;
	else
		back(k+1);}}
int main()
{f>>n;
back(1);
h<<2*z;
return 0;}