我审查了你的法典,从我可以认为是理想的解决办法来看,实际上不需要点人来开展这一方案。 首先,由于“火焰火焰”功能并未真正恢复任何必要的信息,因此更有必要以一个真空的返回条目来设置这种功能。 其次,由于这一职能所需的投入变量只能作为数值通过,因此实际上没有必要发送点名。

为了尽量减少对你的法典的起码改动,可以在你的职能中发表以下声明,同时重述“印本”声明。

    //double remainingCash = *pRemainingCash;           // Not needed
    //pRemainingCash = &remainingCash;

    //pRemainingCash = remainingCash - totalCost;


    if (*pRemainingCash >= totalCost)
    {
        printf("You have purchased %d tickets, and you have %.2f remaining.",totalTickets, *pRemainingCash - totalCost);    // Note remainder calculation
    }

这在码头产生了以下试验产出。

craig@Vera:~/C_Programs/Console/TicketPurchase/bin/Release$ ./TicketPurchase 
How much money do you have to purchase tickets?
800
How many child tickets would you like to purchase?
4
How many adult tickets would you like to purchase?
4
You have purchased 8 tickets, and you have 384.00 remaining.

Noting the observations of the code and simplifying things, following is a refactored version of your program.

#include <stdio.h>

#define ADULT_TICKET_PRICE 69.00                                                    //define constants
#define CHILD_TICKET_PRICE 35.00

void PurchaseTickets(double pRemainingCash, int adultTickets, int childTickets);    //declare function PurchaseTickets()

int main(void)
{
    double funds;
    int childTickets;
    int adultTickets;

    printf("How much money do you have to purchase tickets? ");
    if(scanf("%lf", &funds) != 1)                       //check for errors in user input
    {
        printf("Invalid input, exiting program.
");
        return 1;                                       //will exit program if invalid characters are entered
    }

    printf("How many child tickets would you like to purchase? ");
    if(scanf("%d", &childTickets) != 1)                 //check for errors in user input
    {
        printf("Invalid input, exiting program.
");
        return 1;                                       //will exit program if invalid characters are entered
    }

    printf("How many adult tickets would you like to purchase? ");
    if(scanf("%d", &adultTickets) != 1)                 //check for errors in user input
    {
        printf("Invalid input, exiting program.
");
        return 1;                                       //will exit program if invalid characters are entered
    }

    PurchaseTickets(funds, adultTickets, childTickets);

    return 0;
}

/*****************************************************************************************
 *
 *  Function:  PurchaseTickets()
 *
 *  Parameters:
 *
 *      pRemainingCash - points to a variable containing the amt of cash from user
 *      adultTickets - specifies the number of adult tickets the user wants to buy
 *      childTickets - specifies the number of child tickets the user wants to buy
 *
 *  Description:
 *
 *      The function will determind if the user has enough money to purchase the
 *      specified number of tickets. If they do, the function deducts the proper funds
 *      from their remaining cash and returns the total number of tickets purchased.
 *      if they do not the function returns 0.
 *
*****************************************************************************************/

void PurchaseTickets(double pRemainingCash, int adultTickets, int childTickets)
{
    double adultCost = (adultTickets * ADULT_TICKET_PRICE);
    double childCost = (childTickets * CHILD_TICKET_PRICE);
    double totalCost = adultCost + childCost;

    int totalTickets = adultTickets + childTickets;

    pRemainingCash -= totalCost;

    if (pRemainingCash >= 0.00)
    {
        printf("You have purchased %d tickets, and you have %.2f remaining.
",totalTickets, pRemainingCash);
    }

    else
    {
        printf("You do not have enough money to purchase the tickets.
");
    }

    return;
}

注:

• The return value for the "PurchaseTickets" function was changed to "void" since there appears to be no use for an integer return value.
• All variables are passed as values in lieu of using any variable pointers.
• Unneeded variables were removed to simplify calculations and comparisons.

经过这些改进,对该方案和机票购买功能进行了一系列额外测试。

craig@Vera:~/C_Programs/Console/TicketPurchase/bin/Release$ ./TicketPurchase 
How much money do you have to purchase tickets? 300.00
How many child tickets would you like to purchase? 4
How many adult tickets would you like to purchase? 4
You do not have enough money to purchase the tickets.
craig@Vera:~/C_Programs/Console/TicketPurchase/bin/Release$ ./TicketPurchase 
How much money do you have to purchase tickets? 600
How many child tickets would you like to purchase? 4
How many adult tickets would you like to purchase? 4
You have purchased 8 tickets, and you have 184.00 remaining.

概括而言,通过可变的地址而不是职能中可变的数值,是有正当理由的,但应始终认识到确定是否需要这种功能的背景。 或许应当就确定何时点人受益的职能寻求更多的指导。

这是一个泥土。 在不重复@NoDakker的评论的情况下,下文是显示所需业务的缩略本。 注意一些变数已重新命名(并删除评论),以提高清晰度。

// heading stuff omitted for brevity
int main(void)
{
    double funds;
    int childTickets;
    int adultTickets;

    /* Get funds */ // omitted for brevity

    /* Get # of Child tickets */

    /* Get # of Adult tickets */

    int totTckts = PurchaseTickets( &funds, adultTickets, childTickets );

    // Notice that the function performs its task.
    // Reporting those results belongs in the calling function
    if( totTckts )
        printf( "%d tickets, and you have %.2f remaining.", totTckts, funds );
    else
        printf( "Insufficient funds to purchase those tickets." );

    return 0;
}

int PurchaseTickets( double *pFunds, int nAdult, int nChild )
{
    double Cost
        = (nAdult * ADULT_TICKET_PRICE)
        + (nChild * CHILD_TICKET_PRICE);

    if( *pFunds < Cost ) // Insufficient available funds?
        return 0; // no show

    *pFunds -= Cost; // subtract cost from "double funds;" variable in main()

    return nAdult + nChild; // return # of purchased tickets
}