再菜一次，！！再菜一次

[willpufo]

win32 api 中产生随机数的函数是什么？？有没有？？？

先谢了！！

[macenjie]

srand
Sets a random starting point.

void srand( unsigned int seed );

Routine Required Header Compatibility
srand <stdlib.h> ANSI, Win 95, Win NT


For additional compatibility information, see Compatibility in the Introduction.

Libraries

LIBC.LIB Single thread static library, retail version
LIBCMT.LIB Multithread static library, retail version
MSVCRT.LIB Import library for MSVCRT.DLL, retail version


Return Value

None

Parameter

seed

Seed for random-number generation

Remarks

The srand function sets the starting point for generating a series of pseudorandom integers. To reinitialize the generator, use 1 as the seed argument. Any other value for seed sets the generator to a random starting point. rand retrieves the pseudorandom numbers that are generated. Calling rand before any call to srand generates the same sequence as calling srand with seed passed as 1.

Example

/* RAND.C: This program seeds the random-number generator
* with the time, then displays 10 random integers.
*/

#include <stdlib.h>
#include <stdio.h>
#include <time.h>

void main( void )
{
int i;

/* Seed the random-number generator with current time so that
* the numbers will be different every time we run.
*/
srand( (unsigned)time( NULL ) );

/* Display 10 numbers. */
for( i = 0; i < 10;i++ )
printf( " %6d\n", rand() );
}


Output

6929
8026
21987
30734
20587
6699
22034
25051
7988
10104

[macenjie]

rand
Generates a pseudorandom number.

int rand( void );

Routine Required Header Compatibility
rand <stdlib.h> ANSI, Win 95, Win NT


For additional compatibility information, see Compatibility in the Introduction.

Libraries

LIBC.LIB Single thread static library, retail version
LIBCMT.LIB Multithread static library, retail version
MSVCRT.LIB Import library for MSVCRT.DLL, retail version


Return Value

rand returns a pseudorandom number, as described above. There is no error return.

Remarks

The rand function returns a pseudorandom integer in the range 0 to RAND_MAX. Use the srand function to seed the pseudorandom-number generator before calling rand.

Example

/* RAND.C: This program seeds the random-number generator
* with the time, then displays 10 random integers.
*/

#include <stdlib.h>
#include <stdio.h>
#include <time.h>

void main( void )
{
int i;

/* Seed the random-number generator with current time so that
* the numbers will be different every time we run.
*/
srand( (unsigned)time( NULL ) );

/* Display 10 numbers. */
for( i = 0; i < 10;i++ )
printf( " %6d\n", rand() );
}


Output

6929
8026
21987
30734
20587
6699
22034
25051
7988
10104


Floating-Point Support Routines

See Also srand


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[macenjie]

RAND( ) Function
Example See Also

Returns a random number between 0 and 1.

Syntax

RAND([nSeedValue])

Returns

Numeric

Arguments

nSeedValue

Specifies the seed value that determines the sequence of values RAND( ) returns.

RAND( ) returns the same sequence of random numbers if you use the same seed value for nSeedValue the first time you issue RAND( ) followed by subsequent RAND( ) function calls without nSeedValue.

If nSeedValue is negative the first time you issued RAND( ), a seed value from the system clock is used. To achieve the most random sequence of numbers, issue RAND( ) initially with a negative argument and then issue RAND( ) without an argument.

If you omit nSeedValue, RAND( ) uses a default seed value of 100,001.

[willpufo]

What ???
Is it???
c and unix's run-time library??
api??!!