Compilare: main.c: In function 'back': main.c:4:67: warning: unused variable 'j' [-Wunused-variable] 4 | int v[MAXN],f[MAXN+1],n;FILE*fin;FILE*fout;void back(int d){int i,j;if(d == n){for(i = 0; i < n;i++)fprintf(fout,"%d ",v[i]);fprintf(fout,"\n");}else for(i = 1; i <= n;i++){if(f[i] == 0){v[d] = f[i] = i;back(d+1);f[i] = 0;}}}int main(){fin = fopen("permutari.in","r");fout = fopen("permutari.out","w");fscanf(fin,"%d",&n);back(0);} | ^