Question

我此刻正在尝试学习，但发送给我的文件不正确。我尝试修复了一些事情，但它开始了，然后它就崩溃了。我学习动态记忆，所以我不知道。这是realloc（）;

的代码

 #include <stdio.h> /* printf, scanf, NULL */

    #include <stdlib.h> /* malloc, free, rand */

    int main ()

{

 int count=0,i;

 int *stations=NULL,*ptrToStations=NULL;



for(i=1;i<=7;i++,count++)
    {

ptrToStations=(int*)realloc(stations,count*sizeof(int));

if(ptrToStations!=NULL)//заделили сме памет

 { stations = ptrToStations;

 ptrToStations[count]=i;}

    }

for(i=0;i<7;i++)

printf("%d",stations[i]);

printf("\n");



//добавяне на 8 елемент

ptrToStations=(int*)realloc(stations,++count*sizeof(int));

if(ptrToStations!=NULL)//заделили сме памет

 { stations = ptrToStations;

 ptrToStations [count-1]=count;}



 for(i=0;i<count;i++)

printf("%d",stations[i]);

printf("\n");

int x=3;

//преместваме елементите с един назад

for(i=x;i<count;i++)


ptrToStations[i-1]=ptrToStations[i];

//премахване на 8 елемент

ptrToStations=(int*)realloc(stations,--count*sizeof(int));

if(ptrToStations!=NULL)//заделили сме памет



 stations = ptrToStations;



for(i=0;i<count;i++)


printf("%d",stations[i]);

printf("\n");


 free (ptrToStations);

 free (stations);

 return 0;

}

Answer 1

你在这里遇到了几个问题

最后双重释放相同的内存块
count应该从1开始。在第一次迭代时，你试图将内存块的大小改为0字节
出于数组绑定错误 ptrToStations [数] = I;

您的代码应该看起来像这样

#include <stdio.h> /* printf, scanf, NULL */

    #include <stdlib.h> /* malloc, free, rand */

    int main ()

{

 int count=1,i;

 int *stations=NULL,*ptrToStations=NULL;



for(i=1;i<=7;i++,count++){

    ptrToStations=(int*)realloc(stations,count*sizeof(int));

    if(ptrToStations != NULL) { 
        stations = ptrToStations;
        ptrToStations[count-1]=i;
        for(i=0;i<count;i++)
            printf("%d",stations[i]);
        printf("\n");
    }
}





//добавяне на 8 елемент

ptrToStations=(int*)realloc(stations,++count*sizeof(int));

if(ptrToStations!=NULL){ 
    stations = ptrToStations;
    ptrToStations [count-1]=count;
    }



 for(i=0;i<count;i++)
    printf("%d",stations[i]);
printf("\n");

int x=3;

//преместваме елементите с един назад

for(i=x;i<count;i++)
    ptrToStations[i-1]=ptrToStations[i];

//премахване на 8 елемент

ptrToStations=(int*)realloc(stations,--count*sizeof(int));

if(ptrToStations!=NULL) {
    stations = ptrToStations;
    for(i=0;i<count;i++)
        printf("%d",stations[i]);
printf("\n");
}


 free (stations);

 return 0;

}

动态内存新功能。 realloc（）;

1 个答案: