Recursion Visualization.c

/*      *visualising recusrion*
* ShowFun() keeps track of the recursion
* and visualises the calls/returns
* accordingly. You can visualise any
* kind of recursion function, just call
* ShowFun() with valid arguments at entry
* and exit
*/
#include <stdio.h>

void ShowFun(char*,int,char);

//test recursion function
void f(int n) {
    //enter
    ShowFun("Enter", n, '+');
    if (n <= 0) {
        //exit-conditional
        ShowFun("Exir-Conditional", n, '-');
        return;
    }
    else {
        f(n - 1);
        f(n - 1);
    }
    //exit-default
    ShowFun("Exit-Default", n, '-');
}

int main()
{
    f(3);
    return 0;
}

void ShowFun(char* str, int n, char op) {
    static int i = 0;

    if (op == '+') ++i;
    for (int j = 1; j < i; j++)printf("|\t");
    printf("%s f(%d): %d\n", str, n, i);
    for (int j = 1; j < i; j++)printf("|\t");
    printf("\n");

    if (op == '-') --i;
}