C++随机数产生方法
各位C++高手,初学C++,有些问题需要请教一下,描述如下:我在VS2010中用rand函数产生随机数,用srand函数设置随机变量的种子,虽然我srand的参数每次不同,但产生的随机数却每次都相同,我现在很困惑,不知该如何解决,请各位高手不惜赐教,一下是我的代码
for(int i=0;i<100;i++)
{
if(leader[0]=i+1)
{
for(int j=0;j<7;j++)
{
male[i][j]=leader[j];
}
continue;
}
//产生男性基本信息随机数据
male[i][0]=i;
srand(i);//设置随机种子
for(int j=1;j<4;j++)
{
male[i][j]=rand()%100+1;
}
//产生男性偏好信息随机数据
male[i][4]=rand()%98+1;
male[i][5]=rand()%98+1;
while((male[i][4]+male[i][5])>=100)
{
male[i][5]=rand()%98+1;
}
male[i][6]=100-male[i][4]-male[i][5];
} C++
[解决办法]
srand调用一次就够了。
一般在main函数最开始调用:srand(time(0));
[解决办法]
C:\Program Files\Microsoft Visual Studio 10.0\VC\crt\src\rand.c
/***
*rand.c - random number generator
*
* Copyright (c) Microsoft Corporation. All rights reserved.
*
*Purpose:
* defines rand(), srand() - random number generator
*
*******************************************************************************/
#include <cruntime.h>
#include <mtdll.h>
#include <stddef.h>
#include <stdlib.h>
/***
*void srand(seed) - seed the random number generator
*
*Purpose:
* Seeds the random number generator with the int given. Adapted from the
* BASIC random number generator.
*
*Entry:
* unsigned seed - seed to seed rand # generator with
*
*Exit:
* None.
*
*Exceptions:
*
*******************************************************************************/
void __cdecl srand (
unsigned int seed
)
{
_getptd()->_holdrand = (unsigned long)seed;
}
/***
*int rand() - returns a random number
*
*Purpose:
* returns a pseudo-random number 0 through 32767.
*
*Entry:
* None.
*
*Exit:
* Returns a pseudo-random number 0 through 32767.
*
*Exceptions:
*
*******************************************************************************/
int __cdecl rand (
void
)
{
_ptiddata ptd = _getptd();
return( ((ptd->_holdrand = ptd->_holdrand * 214013L
+ 2531011L) >> 16) & 0x7fff );
}