/* * File: protect.c * --------------- * This file defines the function ProtectedIntegerField, * which might be useful in a financial application, in * which it was important to guard against having someone * forge extra digits at the beginning of a number. */#include <stdio.h>#include "genlib.h"#include "strlib.h"/* Function prototypes */string ProtectedIntegerField(int n, int places);string ConcatNCopies(int n, string str);/* Main program */main(){    printf("$%s.00\n", ProtectedIntegerField(123, 8));}string ProtectedIntegerField(int n, int places){    string numstr, fill;    numstr = IntegerToString(n);    fill = ConcatNCopies(places - StringLength(numstr), "*");    return (Concat(fill, numstr));}/* * Function: ConcatNCopies * Usage: newstr = ConcatNCopies(n, str); * -------------------------------------- * This function creates a new string consisting of n * copies of str concatenated together.  For example, * the call ConcatNCopies(4, "AB") returns the string * "ABABABAB".  This implementation is quite inefficient, * both in its running time and use of memory, and should * not be used in practical applications. */string ConcatNCopies(int n, string str){    string result;    int i;    result = "";    for (i = 0; i < n; i++) {        result = Concat(result, str);    }    return (result);}