I am trying to sort the multiple arrays based on the ascending order of one array. Here is the example:

int a[10] = {55140, 32294, 33321, 64321, 55312}
float b[10] = {11.11, 202.22, 3213.21, 144.32, 1.32}
const char* c[10] = { , -, -, -,  }
unsigned char* d[10] = {22DS3K, 1FGJ29, 21FD43, 98DS03, 56DK23}

Now, after arranging the array 'a' in ascending order I want to sort the other arrays. The output should look like as follows:

a[10] = {32294, 33321, 55140, 55312, 64321}
b[10] = {202.22, 3213.21, 11.11, 1.32, 144.32}
c[10] = {-, -,  ,  , -}
d[10] = {1FGJ29, 21FD43, 22DS3K, 56DK23, 98DS03}

Arranging the ascending order works fine. But, I am unable to sort the other arrays. I woould like to create a function to use it in my main function. Pleased to hear some suggestions.

I have seen the below post, but did not help me.

Sorting an array based on another in C

Here is the code that I have tried:

struct Data{
    int a[10]; 
    float b[10];
    const char* c[10];
    unsigned char* d[10];
} data;

int data_a[10];
float data_b[10];
const char* data_c[10];
unsigned char* d[10];


void ascending(int *t; int N){
int i,j,tmp;
for(i=0;j<N;j  ){
  for(j=i 1;j<N;j  ){
     if(t[i] > t[j]){
       tmp=t[i];
       t[i]=t[j];
       t[j]=tmp;
}}}}

int main(){
   int i;
   for(i=0;i<5;i  ){
   data.a[i] = data_a[i];
   data.b[i] = data_b[i];
   data.c[i] = data_c[i];
   data.d[i] = data_d[i];
   }
   ascending(data.a, 5);
   for(i=0;i<5;i  ){
      printf("Data is %d,%.2f,%s,%hhn\n", data.a[i],data.b[i],data.c[i],data.d[i]};
   }}

May I know if I am missing something or doing something completely wrong?

CodePudding user response：

Keeping such a set of arrays in synch is a nightmare. What you seem to want is an array of structs instead of 5 separate arrays.

If I get you right, this is what would fit your needs better: (Also your initializers don't really match the data type of your arrays c and d.)

typedef struct data_s {
  int a;
  float b;
  const char *c;
  const char *d;
} data_t;

data_t data[10] = 
{
  [0] = {.a=55140, .b=11.11,   .c=" ", .d="22DS3K"},
  [1] = {.a=32294, .b=202.22,  .c="-", .d="1FGJ29"},
  [2] = {.a=33321, .b=3213.21, .c="-", .d="21FD43"},
  [3] = {.a=64321, .b=144.32,  .c="-", .d="98DS03"},
  [4] = {.a=55312, .b=1.32,    .c=" ", .d="56DK23"}
};

Then you can sort (just use qsort) for member a of your struct and as you will swap whole structs at once, the corresponding other members will be sorted accordingly:

int compare_a(const void *data1, const void*data2)
{
  return ((data_t*)data2)->a - ((data_t*)data1)->a;
}

int compare_d(const void *data1, const void*data2)
{
  return strcmp(((data_t*)data1)->d, ((data_t*)data2)->d);
}


int main(void)
{
...
  // optional:
  // Populate the missing fields with some default data
  size_t num_elem = sizeof(data)/sizeof(data[0]);
  for (size_t i = 5; i < num_elem; i  )
  {
    data[i].a = (int)i * 111;
    data[i].b = i * 1.11;
    data[i].c = "none";
    data[i].d = "";
  }

  // Sort for field a
  qsort(data, num_elem, sizeof (data[0]), compare_a);


  // Variant: Size unknown, use dynamic memory allocation
  size_t num_elem2 = 123;
  data_t *data2 = malloc(num_elem2 * sizeof (*data2));
  for (size_t i = 0; i < num_elem; i  )
  {
    data2[i].a = (int)i * 111;
    data2[i].b = i*1.11;
    data2[i].c = "none";
    data2[i].d = "";
  }
  // Sort for field d
  qsort(data, num_elem, sizeof (data[0]), compare_d);
}