fork system call

Question

How many process are created by the program?
int main(){
    int i;
    for(i=0;i<4;i++)
    fork();
    return 0;
}

Can I write like this ?

fork();

fork();

fork();

fork();

Comments

i got only 7 child process using diagram approach .pls someone explain this ?

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In fork() related problems , use direct formula if possible , that less time consuming and give accurate result .

Formula  is :

Number of process created = {(2ⁿ) -1)+1 } where (2ⁿ) -1 = number of Child Process  and 1 is for Parent Process. 

Answer 1

Formula for this fork() related problem is

Total number of process created ={ (2ⁿ) -1)+1 }

where { (2ⁿ) -1} = number of Child Process  and 1 is for Parent Process. 

Now here fork() is called 4 times .  That means n = 4  .  so put n=4 in above formula we get total number of process created is 16.

Among which 15 =2ⁿ - 1 are child process. And 1 is parent process. 

so answer is 16 here .