Qsort usage)

Quick sorting qsort is really powerful

I. Sorting int-type Arrays

Int num [100];

Int CMP (const void * a, const void * B)
{
Return * (int *) A-* (int *) B;
}

Qsort (Num, 100, sizeof (Num [0]), CMP );

2. Sort char array (same as int type)

Char word [100];

Int CMP (const void * a, const void * B)
{
Return * (char *) A-* (int *) B;
}

Qsort (word, 100, sizeof (word [0]), CMP );

Iii. Sort double-type Arrays

Double in [100];

Int CMP (const void * a, const void * B)
{
Return * (double *) A> * (double *) B? 1:-1;
}

Qsort (in, 100, sizeof (in [0]), CMP );

4. sorting the struct at a level

Struct sample
{
Double data;
Int Other;
} S [100]

// Sort by data values from small to large struct

Int CMP (const void * a, const void * B)
{
Return (* (sample *) a). Data <(* (sample *) B). Data? -1: 1;
}

Qsort (S, 100, sizeof (s [0]), CMP );

5. List struct

Struct sample
{
Int X;
Int y;
} S [100];

// Sort by X from small to large, and sort by Y from large to small when X is equal

Int CMP (const void * a, const void * B)
{
Struct sample * c = (sample *);
Struct sample * D = (sample *) B;
If (c-> X! = D-> X) return C-> X-D-> X;
Else return D-> Y-C-> Y;
}

Qsort (S, 100, sizeof (s [0]), CMP );

6. Sort strings

Struct sample
{
Int data;
Char STR [100];
} S [100];

// Sort the string 'str' in alphabetical order.

Int CMP (const void * a, const void * B)
{
Return strcmp (* (sample *) A)-> STR, (* (sample *) B)-> Str );
}

Qsort (S, 100, sizeof (s [0]), CMP );

Append a complete vertex code to sort the string two-dimensional array:

# Include <stdio. h>
# Include <stdlib. h>
# Include <string. h>

Char s [1, 2001] [2, 1001];

Int CMP (const void * a, const void * B ){
Return strcmp (char *) A, (char *) B );
}

Int main (){
Int I, N;
Scanf ("% d", & N );
Getchar ();
For (I = 0; I <n; I ++) gets (s [I]);
Qsort (S, N, 1001 * sizeof (char), CMP );
For (I = 0; I <n; I ++) puts (s [I]);
Return 0;
}

Quick sorting qsort is really powerful

I. Sorting int-type Arrays

Int num [100];

Int CMP (const void * a, const void * B)
{
Return * (int *) A-* (int *) B;
}

Qsort (Num, 100, sizeof (Num [0]), CMP );

2. Sort char array (same as int type)

Char word [100];

Int CMP (const void * a, const void * B)
{
Return * (char *) A-* (int *) B;
}

Qsort (word, 100, sizeof (word [0]), CMP );

Iii. Sort double-type Arrays

Double in [100];

Int CMP (const void * a, const void * B)
{
Return * (double *) A> * (double *) B? 1:-1;
}

Qsort (in, 100, sizeof (in [0]), CMP );

4. sorting the struct at a level

Struct sample
{
Double data;
Int Other;
} S [100]

// Sort by data values from small to large struct

Int CMP (const void * a, const void * B)
{
Return (* (sample *) a). Data <(* (sample *) B). Data? -1: 1;
}

Qsort (S, 100, sizeof (s [0]), CMP );

5. List struct

Struct sample
{
Int X;
Int y;
} S [100];

// Sort by X from small to large, and sort by Y from large to small when X is equal

Int CMP (const void * a, const void * B)
{
Struct sample * c = (sample *);
Struct sample * D = (sample *) B;
If (c-> X! = D-> X) return C-> X-D-> X;
Else return D-> Y-C-> Y;
}

Qsort (S, 100, sizeof (s [0]), CMP );

6. Sort strings

Struct sample
{
Int data;
Char STR [100];
} S [100];

// Sort the string 'str' in alphabetical order.

Int CMP (const void * a, const void * B)
{
Return strcmp (* (sample *) A)-> STR, (* (sample *) B)-> Str );
}

Qsort (S, 100, sizeof (s [0]), CMP );

Append a complete vertex code to sort the string two-dimensional array:

# Include <stdio. h>
# Include <stdlib. h>
# Include <string. h>

Char s [1, 2001] [2, 1001];

Int CMP (const void * a, const void * B ){
Return strcmp (char *) A, (char *) B );
}

Int main (){
Int I, N;
Scanf ("% d", & N );
Getchar ();
For (I = 0; I <n; I ++) gets (s [I]);
Qsort (S, N, 1001 * sizeof (char), CMP );
For (I = 0; I <n; I ++) puts (s [I]);
Return 0;
}