TD-SCDMA中Midamble码的具体作用

//  条件运算符和条件表达式
有一种 if 语句:
if (a>b)
max=a;
else
max=b;

可以把上面的 if 语句改写成:
max=(a>b)?a:b;
赋值号右侧的"(a>b)?a:b"是一个"条件表达式"。"?"是条件运算符。
如果(a>b)条件为真，则条件表达式的值等于a;否则取值b。

条件运算符由两个符号(?和:)组成,必须一起使用。
要求有3个操作对象，称为三目（元）运算符。

条件表达式的一般形式为:
表达式1?表达式2:表达式3

//  选择结构的嵌套
#include "stdafx.h"

int _tmain(int argc, _TCHAR* argv[])
{
int x,y;
scanf_s("%d",&x);
if(x<0)
y=-1;
else
if(x==0) y=0;
else y=1;
printf("x=%d,y=%d\n",x,y);
return 0;
}

#include "stdafx.h"

int _tmain(int argc, _TCHAR* argv[])
{
int x,y;
scanf_s("%d",&x);
if(x>=0)
if(x>0) y=1;
else    y=0;
else        y=-1;
printf("x=%d,y=%d\n",x,y);
return 0;
}

//  用switch语句实现多分支选择结构
switch 语句是多分支选择语句。
#include "stdafx.h"

int _tmain(int argc, _TCHAR* argv[])
{
char grade;
scanf_s("%c",&grade,1);
printf("Your score:");
switch(grade)
{
case 'A' :printf("85~100\n");break;
case 'B' :printf("70~84\n");break;
case 'C' :printf("60~69\n");break;
case 'D' :printf("<60\n");break;
default:printf("enter data error!\n");
}
return 0;
}

/*等级grade定义为字符变量，从键盘输入一个大写字母，赋给变量grade,switch得到grade的值
并把它和各case中给定的值('A','B','C','D'之一)相比较，
如果和其中之一相同（称为匹配），则执行该case后面的语句（即printf语句）。
break语句，它的作用是使流程转到switch语句的末尾(即右花括号处)*/

#include "stdafx.h"

int _tmain(int argc, _TCHAR* argv[])
{
void action1(int,int),action2(int,int);
char ch;
int a=15,b=23;
ch=getchar();
switch(ch)
{
case 'a':
case 'A':action1(a,b);break;
case 'b':
case 'B':action2(a,b);break;
default:putchar('\a');
}
return 0;
}

void action1(int x,int y)
{
printf("x+y=%d\n",x+y);
}

void action2(int x,int y)
{
printf("x*y=%d\n",x*y);
}

//  选择结构程序综合举例
判断某一年是否为闰年
1.
#include "stdafx.h"

int _tmain(int argc, _TCHAR* argv[])
{
int year,leap;
printf("enter year:");
scanf_s("%d",&year);
if(year%4==0)
{
if(year%100==0)
{
if(year%400==0)
leap=1;
else
leap=0;
}
else
leap=1;
}
else
leap=0;
if(leap)
printf("%d is ",year);
else
printf("%d is not ",year);
printf("a leap year.\n");
return 0;
}

2.
#include "stdafx.h"

int _tmain(int argc, _TCHAR* argv[])
{
int year,leap;
printf("enter year:");
scanf_s("%d",&year);
if(year%4!=0)
leap=0;
else if(year%100!=0)
leap=1;
else if(year%400!=0)
leap=0;
else
leap=1;
if(leap)
printf("%d is ",year);
else
printf("%d is not ",year);
printf("a leap year.\n");
return 0;
}

3.
#include "stdafx.h"

int _tmain(int argc, _TCHAR* argv[])
{
int year,leap;
printf("enter year:");
scanf_s("%d",&year);
if((year%4==0&&year%100!=0)||(year%400==0))
leap=1;
else
leap=0;
if(leap)
printf("%d is ",year);
else
printf("%d is not ",year);
printf("a leap year.\n");
return 0;
}

4.
#include "stdafx.h"

int _tmain(int argc, _TCHAR* argv[])
{
int year;
bool leap;
scanf_s("%d",&year);
if(year%4==0)
{
if(year%100==0)
{
if(year%400==0)
leap=true;
else
leap=false;
}
else
leap=true;
}
else
leap=false;

if(leap==true)
printf("%d is ",year);
else
printf("%d is not ",year);
printf("a leap year.\n");
return 0;
}

求ax*x+bx+c=0方程的解
#include "stdafx.h"
#include "math.h"

int _tmain(int argc, _TCHAR* argv[])
{
double a,b,c,disc,x1,x2,realpart,imagpart;
scanf_s("%lf,%lf,%lf",&a,&b,&c);
printf("The equation");
if(fabs(a)<=1e-6)
printf("is not a quadratic\n");
else
{
disc=b*b-4*a*c;
if(fabs(disc)<=1e-6)
printf("has two equal roots:%8.4f\n",-b/(2*a));
else
if(disc>1e-6)
{
x1=(-b+sqrt(disc))/(2*a);
x2=(-b-sqrt(disc))/(2*a);
printf("has distinct real roots:%8.4f and %8.4f\n",x1,x2);
}
else
{
realpart=-b/(2*a);
imagpart=sqrt(-disc)/(2*a);
printf("%8.4f+%8.4fi\n",realpart,imagpart);
printf("%8.4f-%8.4fi\n",realpart,imagpart);
}
}
return 0;
}

运输公司对用户计算运输费用
#include "stdafx.h"

int _tmain(int argc, _TCHAR* argv[])
{
int c,s;
float p,w,d,f;
printf("please enter price,weight,discount:");
scanf_s("%f,%f,%d",&p,&w,&s);
if(s>=3000)c=12;
else       c=s/250;
switch(c)
{
case 0: d=0;break;
case 1: d=2;break;
case 2:
case 3: d=5;break;
case 4:
case 5:
case 6:
case 7: d=8;break;
case 8:
case 9:
case 10:
case 11: d=10;break;
case 12: d=15;break;
}
f=p*w*s*(1-d/100);
printf("freight=%10.2f\n",f);
return 0;
}