我是编程新手,所以我正在试着写一个小程序,我可以显示汽车信息,也可以将汽车添加到我的“库”中,现在我的out come for 1。显示汽车如下所示:
ID BRAND PICS
bbb188 BMW 1 2 3
AAA-999 VOLVO 4 5 6
CCC-999 CITROEN 1 2 3
但是在我添加了一辆新车之后,PICS没有显示。因此,如果我要添加AAA-111沃尔沃1。这是结果:
bbb188 BMW 1 2 3
AAA-999 VOLVO 4 5 6
CCC-999 CITROEN 1 2 3
AAA-111 VOLVO -398253632 3 3
我只是得到了图片的随机数,总是有3个值。有没有人能帮我做这个,请教我怎么做。
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#define MAX 1000
#define IDSIZE 20
#define BRANDSIZE 50
#define PICSIZE 10
typedef struct{
char id[IDSIZE+1];
char brand[BRANDSIZE+1];
int *pic;
} Car;
void printCar(Car *pCar,int imagecount)
{
printf(" %s ",pCar->id);
printf(" %s ",pCar->brand);
for(int i=0; i<imagecount; i++){
printf(" %d",pCar->pic[i]);
}
printf("\n");
}
Car initCar(char itsId[],char itsBrand[],int *itsPic, int imagecount)
{
Car newCar;
strcpy(newCar.id, itsId);
strcpy(newCar.brand, itsBrand);
newCar.pic = itsPic;
return newCar;
}
void PrintList(Car aLista[],int imagecount, int carcount)
{
for(int i = 0; i<imagecount; i++)
printCar(&aLista[i],carcount);
}
void AddCar(Car aList[], int *pAt, Car theCar)
{
aList[(*pAt)++]=theCar;
}
Car NewCar(Car minapatienter[], int patientCount)
{
Car newCar;
gets(newCar.id);
printf("type in ID \n");
gets(newCar.id);
printf("type in brand\n");
gets(newCar.brand);
bool imageInputDone = false;
int imageCount=0;
while(imageInputDone == false)
{
printf("type in image reference \n");
int newImage;
scanf("%d",&newImage);
newCar.pic = &newImage;
imageCount++;
printf("vill du \n1.Add another image reference \n2.exit\n");
int input;
scanf("%d", &input);
printf("input: %i\n",input);
switch(input)
{
case 1:
printf("Adding one more image\n");
break;
case 2:
printf("Leaving loop\n");
imageInputDone = true;
break;
default:
while (input<1 || input<2)
;
printf("Input correct number\n");
break;
}
return newCar;
}
}
int main(void)
{
int carCount=0;
int imagecount=0;
Car myCar[MAX];
int input;
int test[3]={1,2,3};
int test2[3]={4,5,6};
myCar[0]= initCar("bbb188","BMW", test, 3);
myCar[1] = initCar("AAA-999","VOLVO", test2, 3);
myCar[2] = initCar("CCC-999", "CITROEN", test,3);
carCount=3;
imagecount=3;
do {
printf("1. Show cars \n2. Add car \n");
scanf("%d",&input);
switch(input)
{
case 1:
printf("ID BRAND PICS \n");
PrintList(myCar,carCount, imagecount);
break;
case 2:
AddCar(myCar,&carCount,NewCar(myCar,carCount));
printf("ID BRAND PICS \n");
PrintList(myCar,carCount, imagecount);
} //break;
} while (input < '1'|| input < '2');
return 0;
}
发布于 2019-02-20 02:51:17
您的NewCar
函数有一些问题。newImage
在堆栈内存中。当您执行赋值newCar.pic = &newImage;
时,newCar.pic
将指向未定义的内存区域,因为newImage
超出了它的作用域。更好的方法是,我们只使用它的值,这里不使用地址运算符。还有一件事,newCar.pic
是一个指针(整数数组)。因此,您需要在使用前进行分配。当您添加更多镜像项时,需要重新分配。并且也将pic
初始化为空指针。
下面是我对NewCar
函数的修改:
Car NewCar(Car minapatienter[], int patientCount)
{
Car newCar;
gets(newCar.id);
printf("type in ID \n");
gets(newCar.id);
printf("type in brand\n");
gets(newCar.brand);
newCar.pic = NULL;
bool imageInputDone = false;
int imageCount=0;
while(imageInputDone == false)
{
printf("type in image reference \n");
int newImage;
scanf("%d",&newImage);
// Rellocation
newCar.pic = realloc(newCar.pic, (imageCount+1)*sizeof(int));
newCar.pic[imageCount] = newImage;
imageCount++;
printf("vill du \n1.Add another image reference \n2.exit\n");
int input;
scanf("%d", &input);
printf("input: %i\n",input);
switch(input)
{
case 1:
printf("Adding one more image\n");
break;
case 2:
printf("Leaving loop\n");
imageInputDone = true;
break;
default:
while (input<1 || input<2)
;
printf("Input correct number\n");
break;
}
return newCar;
}
}
发布于 2019-02-20 03:04:28
您可以为每辆车打印相同数量的图像,因为您只有一个全局计数器。每个图像都需要一个计数器:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#define MAX 1000
#define IDSIZE 20
#define BRANDSIZE 50
#define PICSIZE 10
typedef struct Car
{
char id[IDSIZE+1];
char brand[BRANDSIZE+1];
int *pic;
int imagecount;
} Car;
使用此更改,不需要传递打印计数:
void printCar(Car *pCar)
{
printf(" %s ", pCar->id);
printf(" %s ", pCar->brand);
for(int i=0; i<pCar->imagecount; i++)
{
printf(" %d",pCar->pic[i]);
}
printf("\n");
}
初始化时需要保存计数器:
Car initCar(char itsId[], char itsBrand[], int *itsPic, int imagecount)
{
Car newCar;
strcpy(newCar.id, itsId);
strcpy(newCar.brand, itsBrand);
newCar.pic = itsPic;
newCar.imagecount = imagecount;
return newCar;
}
当您打印列表时,您混淆了图像计数和汽车计数:
void PrintList(Car aLista[], int imagecount, int carcount)
{
for(int i = 0; i<imagecount; i++)
printCar(&aLista[i],carcount);
}
这必须是:
void PrintList(Car aLista[], int carcount)
{
for (int i = 0; i < carcount; i++)
printCar(&aLista[i]);
}
将汽车添加到您的数组中基本上是可以的,但您可能会检查是否到达MAX
汽车。
void AddCar(Car aList[], int *pAt, Car theCar)
{
aList[(*pAt)++]=theCar;
}
现在最大的问题是。此函数存在内存使用和奇怪循环的问题。
Car NewCar(void)
{
Car newCar = {0}; // initialze with empty strings and NULL pointers.
// TODO: Replace gets with fgets!
// gets(newCar.id); // WHY read before you prompt??
printf("type in ID \n");
gets(newCar.id);
printf("type in brand\n");
gets(newCar.brand);
bool imageInputDone = false;
int imageCount=0;
while(imageInputDone == false)
{
printf("type in image reference \n");
int newImage;
scanf("%d",&newImage);
imageCount++;
int *newpics = realloc(newCar.pic, (imageCount) * sizeof(int));
newpics[imageCount-1] = newImage;
newCar.pic = newpics;
// TODO: Check for NULL
printf("vill du \n1.Add another image reference \n2.exit\n");
int input;
scanf("%d", &input);
printf("input: %i\n",input);
while (input < 1 || input > 2)
switch(input)
{
case 1:
printf("Adding one more image\n");
break;
case 2:
printf("Leaving loop\n");
imageInputDone = true;
break;
default:
printf("Input correct number\n");
break;
}
newCar.imagecount = imageCount;
return newCar;
}
}
最后..。
int main(void)
{
int carCount=0;
Car myCar[MAX];
int input;
int test[3] = {1,2,3};
int test2[3] = {4,5,6};
myCar[0] = initCar("bbb188", "BMW", test, 3);
myCar[1] = initCar("AAA-999", "VOLVO", test2, 3);
myCar[2] = initCar("CCC-999", "CITROEN", test, 3);
carCount=3;
do
{
printf("1. Show cars \n2. Add car \n");
scanf("%d", &input);
switch(input)
{
case 1:
printf("ID BRAND PICS \n");
PrintList(myCar, carCount);
break;
case 2:
AddCar(myCar, &carCount, NewCar());
printf("ID BRAND PICS \n");
PrintList(myCar, carCount);
} //break;
} while (input < 1 || input > 2); // compare as integers, not characters. Don't use < operator
return 0;
}
代码未经过测试。剩下的错误留给练习。;)
https://stackoverflow.com/questions/54772637
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