Listing: CINEMA.CPP 

#include<stdio.h> 

 #include<mem.h> 

 #include<process.h> 

 int n,a[1001],all2=1,v[1001],total[3],MAX=0; 

 FILE *f; 

 void citire(){ 

 f=fopen("CINEMA.IN","r"); 

 fscanf(f,"%d",&n); 

 for(int i=1;i<=n;i++) 

 fscanf(f,"%d",&a[i]); 

 fclose(f); 

 } 

 void identica(){ 

 memset(v,0,sizeof(v)); 

 int da=1; 

 for(int i=1;i<=n;i++) 

 if(a[i]!=i) 

 da=0; 

 else v[i]=1; 

 if (da){ 

 f=fopen("cinema.out","w"); 

 fprintf(f,"0"); 

 fclose(f); 

 exit(0); 

 } 

 } 

 void gaseste_ciclu(int k){ 

 v[k]=1; 

 int i=a[k],lung=1; 

 while (i!=k) v[i]=1,i=a[i],lung++; 

 if (lung>2) all2=2; 

 total[1]+=lung/2; 

 total[2]+=(lung-1)/2; 

 } 

 void prelucreaza_ciclu(int k){ 

 int c[1001],i=a[k],lung=1; 

 v[k]=1; 

 c[lung]=k; 

  while (i!=k) c[++lung]=i,v[i]=1,i=a[i]; 

 for(i=1;i<=lung/2;i++){ 

 fprintf(f,"%d %d\n",c[i],c[lung-i+1]); 

 int aux=a[c[i]]; 

 a[c[i]]=a[c[lung-i+1]]; 

 a[c[lung-i+1]]=aux; 

 } 

 if (lung>MAX) MAX=lung; 

 } 

 void prelucrare(){ 

 total[1]=total[2]=0; 

 for (int i=1;i<=n;i++) 

 if (!v[i]) gaseste_ciclu(i); 

 f=fopen("cinema.out","w"); 

 fprintf(f,"%d\n",all2); 

 for (int pas=1;pas<=all2;pas++){ 

 fprintf(f,"%d\n",total[pas]); 

 memset(v,0,sizeof(v)); 

 for (i=1;i<=n;i++) 

 if (!v[i]) prelucreaza_ciclu(i); 

 } 

 fclose(f); 

 printf("%d\n",MAX); 

 } 

 void main(){ 

 citire(); 

 identica(); 

 prelucrare(); 

 } 

[cuprins]