＃include stdlib.h
玉泉网站建设公司创新互联公司,玉泉网站设计制作，有大型网站制作公司丰富经验。已为玉泉上1000家提供企业网站建设服务。企业网站搭建\成都外贸网站建设要多少钱，请找那个售后服务好的玉泉做网站的公司定做！
这里面的一个方法就是这样用的。
a= rand()%100 这就表示随机取到0－－100之间的整数
所以，1－2x
那就
a= 1 + rand()%(2*x);
就OK了
完整版纯C程序：
#includestdio.h
#includestdlib.h
#includetime.h
#define N 20
void sel_sort(int [],int); //选择排序
int search(int [],int,int); //查找
void insert(int [],int [],int,int); //插入
int num_by_mechine(void) //产生随机数
main()
{
int a[N],x;
int i,index,b[N+1];
srand(time(NULL)); //为随机数发生器rand（）播种
for(i=0;iN;i++)
a[i]=num_by_mechine();
printf("before sel_sort...\n");
for(i=0;iN;i++)
printf("%4d",a[i]);
printf("\n");
sel_sort(a,N);
printf("after sel_sort...\n");
for(i=0;iN;i++)
printf("%4d",a[i]);
printf("\n");
printf("please input x:");
scanf("%d",x);
index=search(a,x,N);
if(index!=-1)
{
printf("find x,x=a[%d]!\n",index);
printf("delete a[%d]...\n",index);
for(i=index+1;iN;i++)
a[i-1]=a[i];
for(i=0;iN-1;i++)
printf("%4d",a[i]);
}
else
{
printf("no find!\n");
printf("after insert...\n");
insert(a,b,x,N);
for(i=0;iN+1;i++)
printf("%4d",b[i]);
}
}
int num_by_mechine(void)
{
return(rand()%100+1); //产生一个分布在1~100之间的随机整数
}
void sel_sort(int a[],int n)
{
int cur,i,t;
for(cur=0;curn-1;cur++)
for(i=cur;in;i++)
if(a[i]a[cur])
t=a[cur],a[cur]=a[i],a[i]=t;
}
int search(int a[],int x,int n)
{
int front=0,back=n-1,middle;
while(front=back)
{
middle=(front+back)/2;
if(xa[middle])
back=middle-1;
else if(xa[middle])
front=middle+1;
else
return(middle);
}
return -1;
}
void insert(int a[],int b[],int x,int n)
{
int i,j;
for(i=0;in;i++)
b[i]=a[i];
for(i=0;in;i++)
if(a[i]x)
{ for(j=n;ji;j--)
b[j]=b[j-1];
b[i]=x;
return;
}
b[n]=x;
}
下面共有两个程序，程序2 加入了图形显示
程序1
这个程序就是你要的。
# include "stdio.h"
# include "math.h"
# include "stdlib.h"
# include "math.h"
# include "dos.h"
# define MAX_N 3000 /*这个值为N可以定义的最大长度*/
# define N 100 /*产生随机序列的点数，注意不要大于MAX_N*/
/*产生均匀分布的随机变量*/
void randa(float *x,int num);
/*产生瑞利分布的随机变量*/
void randr(float *x,int num);
/*产生标准高斯分布的随机变量*/
void randn(float *x,int num);
/*产生莱斯分布的随机变量*/
void randl(float *x, float a, float b, int num);
void fshow(char *name,float *x,int num);
main()
{
float x[N];
int i;
/*
randa(x,N);
randr(x,N);
randl(x,10,10,N);
*/
randn(x,N);
/*此时x[N]就是所需要的高斯分布的序列*/
/*显示该序列*/
fshow("x",x,N);
getch();
}
void randa(float *x,int num)
{
int i;
struct time stime;
unsigned seed;
gettime(stime);
seed=stime.ti_hund*stime.ti_min*stime.ti_hour;
srand(seed);
for(i=0;inum;i++)
{
x[i]=rand();
x[i]=x[i]/32768;
}
}
void randr(float *x,int num)
{
float x1[MAX_N];
int i;
struct time stime;
unsigned seed;
gettime(stime);
seed=stime.ti_hund*stime.ti_min*stime.ti_hour;
srand(seed);
for(i=0;inum;i++)
{
x1[i]=rand();
x[i]=x1[i]/32768;
x[i]=sqrt(-2*log(x[i]));
}
}
void randn(float *x,int num)
{
float x1[MAX_N],x2[MAX_N];
int i;
struct time stime;
unsigned seed;
gettime(stime);
seed=stime.ti_hund*stime.ti_min*stime.ti_hour;
srand(seed);
for(i=0;inum;i++)
{
x1[i]=rand();
x2[i]=rand();
x1[i]=x1[i]/32768;
x2[i]=x2[i]/32768;
x[i]=sqrt(-2*log(x1[i]))*cos(x2[i]*M_PI);
}
}
void randl(float *x, float a, float b, int num)
{
float x1[MAX_N],x2[MAX_N];
float temp[MAX_N];
int i;
struct time stime;
unsigned seed;
gettime(stime);
seed=stime.ti_hund*stime.ti_min*stime.ti_hour;
srand(seed);
for(i=0;inum;i++)
{
x1[i]=rand();
x2[i]=rand();
x1[i]=x1[i]/32768;
x2[i]=x2[i]/32768;
temp[i]=sqrt(-2*log(x1[i]))*cos(x2[i]*M_PI);
x2[i]=sqrt(-2*log(x1[i]))*sin(x2[i]*M_PI);
x1[i]=temp[i];
x[i]=sqrt((a+x1[i])*(a+x1[i])+(b+x2[i])*(b+x2[i]));
}
}
void fshow(char *name,float *x,int num)
{
int i,sign,L;
float temp;
printf("\n");
printf(name);
printf(" = ");
L=6;
/*按照每行6个数据的格式显示*/
for(i=0;inum;i++)
{
temp=i/L;
sign=temp;
if((i-sign*L)==0) printf("\n");
if(x[i]0) printf(" %f ",x[i]);
else printf("%f ",x[i]);
}
}
程序 2
以下程序加入了图形显示的效果，因此更加直观，你可以参考一下。
/* 作者 Leo_nanjing
时间 2008.5.10
功能 生成各种分布的随机变量,并显示
*/
# include "stdio.h"
# include "math.h"
# include "graphics.h"
# include "math.h"
# include "dos.h"
# define MAX_N 3000
# define N 1000
void randa(float *x,int num);
void randr(float *x,int num);
void randn(float *x,int num);
void randl(float *x, float a, float b, int num);
void fshow(char *name,float *x,int num);
/*用于图形显示的部分*/
void init_graphic(unsigned color);
void plotxy(float *x, float *y, int num,int mode);
void plot(float *y,int num, int mode);
float max(float *x, int num);
float min(float *x, int num);
/*画出该随机序列的分布函数曲线*/
void plotpdf(float *x,int num,int part,int mode);
main()
{
float x[N];
int i;
randn(x,N);
fshow("x",x,N);
getch();
/*以下为图形显示部分*/
init_graphic(0);
/*显示随机序列*/
plot(x,N,1);
getch();
/*显示其分布函数*/
plotpdf(x,N,20,0);
getch();
}
void randa(float *x,int num)
{
int i;
struct time stime;
unsigned seed;
gettime(stime);
seed=stime.ti_hund*stime.ti_min*stime.ti_hour;
srand(seed);
for(i=0;inum;i++)
{
x[i]=rand();
x[i]=x[i]/32768;
}
}
void randr(float *x,int num)
{
float x1[MAX_N];
int i;
struct time stime;
unsigned seed;
gettime(stime);
seed=stime.ti_hund*stime.ti_min*stime.ti_hour;
srand(seed);
for(i=0;inum;i++)
{
x1[i]=rand();
x[i]=x1[i]/32768;
x[i]=sqrt(-2*log(x[i]));
}
}
void randn(float *x,int num)
{
float x1[MAX_N],x2[MAX_N];
int i;
struct time stime;
unsigned seed;
gettime(stime);
seed=stime.ti_hund*stime.ti_min*stime.ti_hour;
srand(seed);
for(i=0;inum;i++)
{
x1[i]=rand();
x2[i]=rand();
x1[i]=x1[i]/32768;
x2[i]=x2[i]/32768;
x[i]=sqrt(-2*log(x1[i]))*cos(x2[i]*M_PI);
}
}
void randl(float *x, float a, float b, int num)
{
float x1[MAX_N],x2[MAX_N];
float temp[MAX_N];
int i;
struct time stime;
unsigned seed;
gettime(stime);
seed=stime.ti_hund*stime.ti_min*stime.ti_hour;
srand(seed);
for(i=0;inum;i++)
{
x1[i]=rand();
x2[i]=rand();
x1[i]=x1[i]/32768;
x2[i]=x2[i]/32768;
temp[i]=sqrt(-2*log(x1[i]))*cos(x2[i]*M_PI);
x2[i]=sqrt(-2*log(x1[i]))*sin(x2[i]*M_PI);
x1[i]=temp[i];
x[i]=sqrt((a+x1[i])*(a+x1[i])+(b+x2[i])*(b+x2[i]));
}
}
void fshow(char *name,float *x,int num)
{
int i,sign,L;
float temp;
printf("\n");
printf(name);
printf(" = ");
L=6;
for(i=0;inum;i++)
{
temp=i/L;
sign=temp;
if((i-sign*L)==0) printf("\n");
if(x[i]0) printf(" %f ",x[i]);
else printf("%f ",x[i]);
}
}
/*以下为图形显示的函数*/
void init_graphic(unsigned color)
{
int graphicdriver,graphicmode;
graphicdriver=DETECT;
graphicmode=1;
initgraph(graphicdriver,graphicmode,"E:\\turboc2\\");
setbkcolor(color);
}
void plotxy(float *x, float*y, int num,int mode)
{
int i;
float max_x,max_y,min_x,min_y;
float x0,y0,x1,y1;
clrscr(0);
cleardevice();
setbkcolor(0);
max_x=max(x,num);
max_y=max(y,num);
min_x=min(x,num);
min_y=min(y,num);
setlinestyle(0,2,1);
line(65,35,65,445);
line(65,445,575,445);
setlinestyle(3,0,1);
line(65,35,575,35);
line(575,35,575,445);
setlinestyle(0,2,1);
if(max_x==min_x)
x0=320;
else
x0=(x[0]-min_x)*500/(max_x-min_x)+70;
if(max_y==min_y)
y0=240;
else
y0=480-((y[0]-min_y)*400/(max_y-min_y)+40);
if(mode==0) circle(x0,y0,2);
for(i=1;inum;i++)
{
if(max_x==min_x)
x1=320;
else
x1=(x[i]-min_x)*500/(max_x-min_x)+70;
if(max_y==min_y)
y1=240;
else
y1=480-((y[i]-min_y)*400/(max_y-min_y)+40);
if(mode==0) circle(x1,y1,2);
line(x0,y0,x1,y1);
x0=x1;y0=y1;
}
printf("\n\n");
printf("%f",max_y);
printf("\n\n\n\n\n\n\n\n\n\n");
printf("\n\n\n");
printf("%f",(max_y+min_y)/2);
printf("\n\n\n\n\n\n\n\n\n\n");
printf("\n\n");
printf("%f",min_y);
printf("\n %f",min_x);
printf(" ");
printf("%f",(max_x+min_x)/2);
printf(" ");
printf("%f",max_x);
}
void plot(float*y, int num,int mode)
{
int i;
float max_x,max_y,min_x,min_y;
float x0,y0,x1,y1;
float x[MAX_N];
clrscr(0);
cleardevice();
setbkcolor(0);
for(i=0;inum;i++) x[i]=i+1;
max_x=max(x,num);
max_y=max(y,num);
min_x=min(x,num);
min_y=min(y,num);
setlinestyle(0,2,1);
line(65,35,65,445);
line(65,445,575,445);
setlinestyle(3,0,1);
line(65,35,575,35);
line(575,35,575,445);
setlinestyle(0,2,1);
if(max_x==min_x)
x0=320;
else
x0=(x[0]-min_x)*500/(max_x-min_x)+70;
if(max_y==min_y)
y0=240;
else
y0=480-((y[0]-min_y)*400/(max_y-min_y)+40);
if(mode==0) circle(x0,y0,2);
for(i=1;inum;i++)
{
if(max_x==min_x)
x1=320;
else
x1=(x[i]-min_x)*500/(max_x-min_x)+70;
if(max_y==min_y)
y1=240;
else
y1=480-((y[i]-min_y)*400/(max_y-min_y)+40);
if(mode==0) circle(x1,y1,2);
line(x0,y0,x1,y1);
x0=x1;y0=y1;
}
printf("\n\n");
printf("%f",max_y);
printf("\n\n\n\n\n\n\n\n\n\n");
printf("\n\n\n");
printf("%f",(max_y+min_y)/2);
printf("\n\n\n\n\n\n\n\n\n\n");
printf("\n\n");
printf("%f",min_y);
printf("\n %f",min_x);
printf(" ");
printf("%f",(max_x+min_x)/2);
printf(" ");
printf("%f",max_x);
}
void plotpdf(float *x,int num,int part,int mode)
{
int i,j;
float max_x,min_x,round,deltax,up,down,sum;
float xl[MAX_N],yl[MAX_N];
sum=0;
max_x=max(x,num);
min_x=min(x,num);
round=max_x-min_x;
deltax=round/part;
xl[0]=min_x;
for(i=1;i=part;i++)
{
xl[i]=min_x+deltax*i;
yl[i-1]=0;
up=xl[i];
down=xl[i-1];
for(j=0;jnum;j++)
{
if((x[j]up) (x[j]=down)) yl[i-1]=yl[i-1]+1;
}
yl[i-1]=yl[i-1]/num/deltax;
}
for(i=0;ipart;i++) sum=sum+yl[i];
plotxy(xl,yl,part,mode);
}
float max(float *x, int num)
{
int i;
float max;
max=x[0];
for(i=1;inum;i++)
{
if(x[i]max) max=x[i];
}
return max;
}
float min(float *x, int num)
{
int i;
float min;
min=x[0];
for(i=1;inum;i++)
{
if(x[i]min) min=x[i];
}
return min;
}
return一句的功能只是把得数的绝对值控制在0~32767之间，关键是next = next * 1103515245 + 12345一句。next变量是静态的，变化以后的值是不消失的，下一次还可用，所以每执行一次next = next * 1103515245 + 12345就获得一个新值，这个新值被return取整除、取余除后控制在0~32767之间就形成了0~32767的随机数。比如第一次，next=1*1103515245 + 12345=1103527590，经return中的对65536取整、对32768取余后就是16838；若再来一次，next已经是1103527590了，那么next = next * 1103515245 + 12345就为next = 1103527590 * 1103515245 + 12345=1217759518843121895；但这个数已经溢出了，实际上表示成了-1770082073，经return中取整取余后返回的就是-27009；可以算出来，再下一次是10113……不过，你这个函数并不能产生真正意义上的“随机”数，因为作为基数的1103515245在每次开始时是不变的，所以只能得出同样的序列，即每次执行都产生16838、-27009、10113……这样一组无限多的数。所以实际的C随机函数rand()的形参并不是void而是一个长整型变量，通常来调用实时时间函数获取实时时间值来得到，因为时间是每时每刻都在变化的，所以充当"1103515245”角色的数就每调用一次的值都不同。这样每次执行就都能得到不重复的序列。至于12345，我想随便取个数都行！仅供参考……
#include stdio.h
#include time.h
#include stdlib.h
//产生n个随机数，依次放在x指向的内存空间
void funRand(int *x, int n) {
srand((unsigned) time(NULL));
for (int i = 0; i n; i++) {
*(x + i) = rand() % (n + 1);
}
}
//统计x指向的内存空间中数据的分段数量，保存在以y指向的内存空间
void funCount(int *x, int n, int *y) {
int count_09 = 0;
int count_1019 = 0;
int count_2029 = 0;
int count_3039 = 0;
int count_4049 = 0;
int count_5059 = 0;
int count_6069 = 0;
int count_7079 = 0;
int count_8089 = 0;
int count_9099 = 0;
int count_100 = 0;
for (int i = 0; i n; i++) {
if (*(x + i) = 0 *(x + i) 10)
*y = ++count_09;
if (*(x + i) = 10 *(x + i) 20)
*(y + 1) = ++count_1019;
if (*(x + i) = 20 *(x + i) 30)
*(y + 2) = ++count_2029;
if (*(x + i) = 30 *(x + i) 40)
*(y + 3) = ++count_3039;
if (*(x + i) = 40 *(x + i) 50)
*(y + 4) = ++count_4049;
if (*(x + i) = 50 *(x + i) 60)
*(y + 5) = ++count_5059;
if (*(x + i) = 60 *(x + i) 70)
*(y + 6) = ++count_6069;
if (*(x + i) = 70 *(x + i) 80)
*(y + 7) = ++count_7079;
if (*(x + i) = 80 *(x + i) 90)
*(y + 8) = ++count_8089;
if (*(x + i) = 90 *(x + i) 100)
*(y + 9) = ++count_9099;
if (*(x + i) == 100)
*(y + 10) = ++count_100;
}
}
//输出x执行的内存空间中的n个数据
void arrayOut(int *x, int n) {
int m = 0;
if (n == 11) {
printf("0-9\t10-19\t20-29\t30-39\t40-49\t50-59\t60-69\t70-79\t80-89\t90-99\t100\n");
for (int i = 0; i n; i++) {
printf("%d\t", *(x + i));
}
} else {
for (int i = 0; i n; i++) {
m = m + 1;
printf("%d\t", *(x + i));
if (m % 10 == 0)
printf("\n");
}
}
printf("\n");
}
int main() {
int i, a[100], num[11] = {0};
funRand(a, 100); //产生随机数
funCount(a, 100, num); //统计
printf("产生的随机数为：\n");
arrayOut(a, 100); //输出数据
printf("各随机数区间分布：\n");
arrayOut(num, 11); //输出统计数据
return 0;
}
一般有两种算法：
算法一产生12个（0，1）平均分布的随机函数，用大数定理可以模拟出正态分布。
算法二用到了数学中的雅可比变换，直接生成正态分布，但此算法在计算很大规模的数时
会出现溢出错误。
测试程序：
#include math.h
#include stdio.h
#include conio.h
#include stdlib.h
#include time.h
double _random(void)
{
int a;
double r;
a=rand()%32767;
r=(a+0.00)/32767.00;
return r;
}
double _sta(double mu,double sigma)
{
int i;
double r,sum=0.0;
if(sigma=0.0) { printf("Sigma=0.0 in _sta!"); exit(1); }
for(i=1;i=12;i++)
sum = sum + _random();
r=(sum-6.00)*sigma+mu;
return r;
}
double _sta2(double mu,double sigma)
{
double r1,r2;
r1=_random();
r2=_random();
return sqrt(-2*log(r1))*cos(2*M_PI*r2)*sigma+mu ;
}
int main()
{
int i;
double mu,sigma;
srand( (unsigned)time( NULL ) );
mu=0.0;
sigma=1.0;
printf("Algorithm 1:\n");
for(i=0;i10;i++)
printf("%lf\t",_sta(mu,sigma));
printf("Algorithm 2:\n");
for(i=0;i10;i++)
printf("%lf\t",_sta2(mu,sigma));
return 0;
}
//由均匀分布的随机数得到正态分布的随机数
#include math.h
float gasdev(idum)
int *idum;
{
static int iset=0;
static float gset;
float fac,r,v1,v2;
float ran1();//产生均匀分布的随机数，可利用系统函数改写
if (iset == 0) {
do {
v1=2.0*ran1(idum)-1.0;
v2=2.0*ran1(idum)-1.0;
r=v1*v1+v2*v2;
} while (r = 1.0);
fac=sqrt(-2.0*log(r)/r);
gset=v1*fac;
iset=1;
return v2*fac;
} else {
iset=0;
return gset;
}
}
原理可找本数值算法方面的书看看。