Question

Check the words in bold. The Fibonacci sequence is the series of numbers 0,1,1, 2, 3, 5, 8,.... Formally, it can be expressed as:

fib0 = 0
fib1 = 1
fibn = fibn-1 + fibn-2

Write a multithreaded program that generates the Fibonacci sequence using the Win32 thread library(not pthreads because it does not work on windows). This program should work as follows: The user will enter on the command line the number of Fibonacci numbers that the program is to generate. The program will then create a separate thread that will generate the Fibonacci numbers, placing the sequence in data that can be shared by the threads (use an array). When the thread finishes execution, the parent thread will output the sequence generated by the child thread. Because the parent thread cannot begin outputting the Fibonacci sequence until the child thread finishes, this will require having the parent thread wait for the child thread to finish.

The program should not terminate or crash while processing invalid data types. It should continue to prompt the user to input the correct data type.

Answer 1

#include<stdio.h>
#include<time.h>
#include<pthread.h>
#include<stdlib.h>
#include<sys/types.h> / need to calculate which I will implement later /

void fibr(void n);
void fibr_1(void k);
signed long long int fibonacci(signed long long int);

int main(){
clock_t begin, end;
double time_spent;
pthread_t tid,tid1;
int result,result1;
signed long long int n=6;
signed long long int m=7;

result=pthread_create(&tid,NULL,fibr,&n);
if(result){
perror("pthread_create");
return 1;
}
result1=pthread_create(&tid1,NULL,fibr,&m);
if(result1){
perror("pthread_create");
return 1;
}
if(pthread_join(tid,NULL)){
perror("pthread_join");
return 1;
}
if(pthread_join(tid1,NULL)){
perror("pthread_join");
return 1;
}
printf("Fib value=%lld\n",n+m);
pthread_exit(NULL);
}
void fibr(void n){
signed long long int *y=n;
signed long long int x=*y;
pthread_t tid2,tid3;
signed long long int i,j;
/* How do I assign values to i , j in order to
achieve the level viz fib(n-2)....fib(n-4) */
if(pthread_create(&tid2,NULL,fibr_1,&i))
{
perror("pthread_create");
}

if(pthread_create(&tid3,NULL,fibr_1,&j))
{
perror("pthread_create");
}
if(pthread_join(tid2,NULL))
{
perror("pthread_join");
}

if(pthread_join(tid3,NULL))
{
perror("pthread_join");
}
/ How to return the values of i, j combined with y . if I do *y+i+j, the result
is not coming correctly */
*y=fibonacci(x);
return NULL;
}

void fibr_1(void k){
long long int *a=k;
long long int b=*a;
*a=fibonacci(b);
return NULL;
}

signed long long int fibonacci(signed long long int x){
if((x==0)||(x==1))
return x;
return fibonacci(x-1)+fibonacci(x-2);
}