This formula is used for computing pi$($pi$),$ and it takes a lot of terms on the right$-$hand side before

pi value is very accurate. Meaning that the bigger the n$,$ the more accurate the pi estimation.

The following serial code uses this formula:

for $($i $=0$; i $$ n; i$++)\{$

if$($i$\%2==0)$

factor$=1$;

else

factor$=-1$;

sum $+=$ factor$/(2*$i$+1)$;

$\}$

pi $=4\mathrm{.}0*$sum;

Write a multithreaded program by using c$++$ that calculates pi using the above formula by dividing the iterations

in the for loop among the threads. To simplify the computations, let's assume that the number of

working threads is $2$ and n$=1000000.$

After the two working threads split the iterations and each thread has its own local sum, they update

the global variable sum, and the parent thread outputs the sum $($i$.$e$.,$ pi estimation$)$ once the

workers have exited.

Note that if there is a critical section, you need to protect it from race condition.