第三章【例3-3】输出单个字符。#includemain(){chara='B',b='O',c='Y';putchar(a);putchar(b);putchar(c);putchar('\n');}【例3-4】用printf函数输出数据。main(){inta=25;floatb=123.4567898;doublec=34567890.1234567;chard='k';printf("a=%d,%5d,%o,%x,%u\n",a,a,a,a,a);printf("b=%f,%lf,%10.4f,%5.4f,%e,%10.2e\n",b,b,b,b,b,b);printf("c=%f,%e,%g\n",c,c,c);printf("d=%c,%8c,%i\n",d,d,d);printf("string=%s,%8s,%8.3s,%-8.3s\n","china","china","china","china");}程序执行结果为:a=25,25,31,19,25b=123.456787,123.456787.123.4568,123.4568,1.23457e+02,1.2e+02c=34567890.123457,3.45679e+07,3.45679e+07d=k,k,107string=china,china,chi,chi【例3-6】用scanf函数输入数据。main(){inta,b,c;printf("inputa,b,c\n");scanf("%d%d%d",&a,&b,&c);printf("a=%d,b=%d,c=%d\n",a,b,c);}程序执行结果为:inputa,b,c↙123a=1,b=2,c=3运行时可按以下任何一种方式输入变量a、b、c的值。①123↙（以一个空格分隔）②1↙（以回车符分隔）2↙3↙③1↙23↙（以一个空格分隔）④12↙（以tab键分隔）3↙⑤123↙（以多个空格分隔）【例3-7】计算任意两整数的和、差、积、商。#include"stdio.h"main(){inta,b,c,d,e,f;printf("pleaseinputtwointegeraandb:\n");scanf("%d%d",&a,&b);c=a+b;d=a-b;e=a*b;f=a/b;printf("%d+%d=%d%d-%d=%d\n",a,b,c,a,b,d);printf("%d*%d=%d%d/%d=%d\n",a,b,e,a,b,f);}程序执行结果为:：pleaseinputtwointegeraandb:151015+10＝2515-10＝515*10＝15015/10=1【例3-8】计算圆柱的体积。定义实型变量radius,high,vol分别表示圆柱的底面半径、高和体积。#definePI3.1415926main(){floatradius,high,vol;printf("Pleaseinputradius&high:");scanf("%f%f",&radius,&high);/*从键盘输入两个实数赋给变量radius,high*/vol=PI*radius*radius*high;printf("radius=%7.2f,high=%7.2f,vol=%7.2f\n",radius,high,vol);}程序执行结果为:：Pleaseinputradius&high:25radius=2.00,high=5.00,vol=62.83【例3-9】计算一元二次方程ax2+bx+c=0的根。(假设b2-4ac>0)#include"math.h"/*为使用求平方根函数sqrt()，必须包含math.h头文件*/main(){floata,b,c,disc,x1,x2;printf("inputa,b,c:");scanf("%f,%f,%f",&a,&b,&c);/*输入方程的三个系数的值*/disc=b*b-4*a*c;/*求判别式的值赋给disc*/x1=(-b+sqrt(disc))/(2*a);x2=(-b-sqrt(disc))/(2*a);printf("\nx1=%6.2fx2=%6.2f\n",x1,x2);}程序执行结果为:inputa,b,c:1,3,2x1=-1.00x2=-2.00【例3-10】按不同格式输出整型与长整型。main(){intnum1=123;longnum2=123456;/*用3种不同格式，输出int型数据num1的值*/printf("num1=%d,num1=%5d,num1=%-5d,num1=%2d\n",num1,num1,num1,num1);/*用3种不同格式，输出long型数据num2的值*/printf("num2=%ld,num2=%8ld,num2=%5ld\n",num2,num2,num2);}程序执行结果为:：num1=123,num1=123,num1=123,num1=123num2=123456,num2=123456,num2=123456【例3-11】输入一个三位正整数，以倒序形式输出它的各位数。（例如：输入123，则输出321）main(){intx,a,b,c;printf("pleaseinputx:");scanf("%d",&x);/*输入一个三位正整数*/c=x%10;/*获得个位数字*/b=x/10%10;/*获得十位数字*/a=x/100;/*获得百位数字*/printf("\nx=%d,daoshu=%d\n",x,100*c+10*b+a);}程序执行结果为:：pleaseinputx:345x=345,daoshu=543【例3-12】输入两个整数，比较它们的大小，并将其中的大数输出。main(){inta,b,max;printf("\ninputtwonumbers:");scanf("%d%d",&a,&b);max=a;if(max100))printf("dataerror!\n");elseif(...
