在一定程度上打印输出跟随零

I am trying to print zeros to a certain length to compare with another numbers which is store as string, I was wondering how to do that?

Edit: added sample code
For example:

printf("%s\n", "References:\n3.141592653"
    "58979323846264338327950288419716939937510582097494459230781640628620899");
printf("Monte Carlo: %d nodes over %d iterations calculated Pi as:\n%1.9f\n", numnodes, 
    final_iters,pi);    //Print the calculated value of pi

The out is

References:
3.14159265358979323846264338327950288419716939937510582097494459230781640628620899
Monte Carlo 16 nodes over 160000 iterations calculated Pi as:
3.142025000

How would I make the actual calculation fill in zeros to the end of the string?

maybe this will help you. in comment the result, maybe there are better solution but this works. in printf the %016 should be change to your max_buffer length or preferred range and don't forget to add 0 after %.

printf("%016f\n\n",3.142025000); //// 000000003.142025


 ///3.14159000000000000000000000000
 #define MAX_BUFFER 32
float pi = 3.141592653;
char digit[MAX_BUFFER]={'\0'};
sprintf(digit, "%f", pi);
int l = strlen(digit);
int dif = MAX_BUFFER-l;
 for(int i=0;i<dif;i++)
 {
     digit[i+l-1]='0';
 }
 printf("%s", digit);

How would I make the actual calculation fill in zeros to the end of the string?

Code could attempt various numeric approaches such as

printf("%1.9f%071d\n", pi, 0); // Print an extra int 0 with wide width padded with '0'
printf("%1.80f\n", pi);        // Print with wide precision - (might not all be 0's)

Yet I worry that specifiers with large width/precision and number specifiers may break some printf() implementation. so I'll add a text approach.

#define PI_STR "3.1415926535" \
    "8979323846264338327950288419716939937510582097494459230781640628620899"
printf("%s\n", "References:\n" PI_STR);

// Remember length of reference pi string
int pi_ref_len = (sizeof PI_STR)  - 1;

...
// Print computed pi & return count of characters printed
int pi_compute_len = printf("%1.9f", pi);

// Use a loop or print a portion of a string "0000...000"
char zeros[sizeof PI_STR];
memset(zeros, '0', sizeof zeros);
//        v--- %s w/precision can print a non-null character terminated char array
printf("%.*s\n", pi_ref_len - pi_compute_len, zeros);