人民邮电出版社《C语言程序设计》贾宗璞许合利主编课后答案第1章1．选择题(1) C (2) B (3) D2．填空题(1)main (2) main (3) 有穷性、确定性、有零个或多个输入、有一个或多个输出、有效性(4) 顺序、分支和循环(5) 自顶向下，逐步细化、模块化设计、结构化编码第2章1．选择题BBCDA DDBBA BBDCB2、填空题(1) 数字、字母、下划线 (2)0 (3) 4、8 (4) (a+b)*c/(a-b) (5) －60 （6）－16 （7）3 （8）6、4、2 （9）0 （10）10、6 （11）5.500000 （12） 12、4（13）double （14） 0 （15）16 （16）6.63、编程题（1）main(){printf("int:%5d\n""float:%5d\n""char:%5d\n""double:%5d\n""long:%5d\n",sizeof(int),+-sizeof(float),sizeof(char),sizeof(double),sizeof(long));}（2）#define RAT 1.60934main(){float k=0.0;printf("input the km:");scanf("%f",&k);printf("\nmile:%f",k*RAT);}第3章1．选择题(1) ～(10)：DDCDCDCDBC2．解析题(1) x=170,x=ㄩㄩㄩ170,x=ㄩㄩㄩ252, x=ㄩㄩㄩ170x=170,x=170ㄩㄩㄩ,x=ㄩㄩㄩ170,x=%6da=513.789185,a=ㄩㄩ513.79,a=513.78918457,a=513.78918457(2) a=3ㄩb=7x=8.5ㄩy=71.82c1=Aㄩc2=a3．编程题(1) main(){int x,y;scanf("%d%d",&x,&y);printf("商数=%d,余数=%d",x/y,x%y);system("pause");}(2)main(){double x,y,z,avg;scanf("%lf%lf%lf",&x,&y,&z);avg=(x+y+z)/3;printf("%.1lf",avg,avg);system("pause");}第4章1．选择题(1)～(10) CCAADCCABD2．填空题(1) ch>='A' && ch<='Z' ch=ch-32(2) x<=10 && x>2 x<=2 && x>-1 y=-1(3) a+b>c && a+c>b && b+c>a a==b&&a==c a==b || a==c || b==c(4) mark/10 k=1 case 9(5) x<0 c=x/10 y!=-23．编程题(1)#include <stdio.h>main(){int x;printf("please input a number:");scanf("%d",&x);if(x%2==0) printf("x is a even number");else printf("x is a odd number");}(2)#include <stdio.h>main(){int x,y;printf("please input a number￡o");scanf("%d",&x);if(x<=-5) printf("the number is error");else if(x<0) {y=x; printf("%d",y);}else if(x==0) {y=x-1;printf("%d",y);}else if(x<10) {y=x+1;printf("%d",y);}else printf("the number is error");}(3)#include <stdio.h>main(){ int a,m;printf("please input a number:");scanf("%d",&a);switch(a/10){ case 0:case 1:case 2:m=1;break;case 3:m=2;break;case 4:m=3;break;case 5:m=4;break;default:m=5;break;}printf("%d",m);}(4)#include <stdio.h>main(){float price,tax;printf("please input the price of product:");scanf("%f",&price);if(price>10000) tax=price*0.05;else if(price>5000) tax=price*0.03;else if(price>1000) tax=price*0.02;else tax=0;printf("%f",tax);}(5)#include <stdio.h>main(){float score;printf("please input the score of student:");scanf("%f",&score);if(score>=85) printf("VERY GOOD");else if(score>=60) printf("GOOD");else printf("BAD");}第5章1．选择题(1)d (2) c (3)a (4)d (5)a (6)d (7)d (8)b (9)d (10)b (11)c (12)b (13)d (14)a (15)c2．填空题(1) ==0 m=m/k k++ (2) 5 4 6 (3) 3*i-2(4) -= *= (5) 8 5 2 (6) j++ i%j==0 j>=i(7)sum<k sum==k j-2 (8) s=0 p=1 j<=i3．改错题(1) 第一处改正： For改为for第二处改正： ave=sum/4改为ave=sum/4.0(2) 第一处改正： j<=9第二处改正： m=100*i+10*j+k3．编程题(1)#include <math.h> main(){int s;float n,t,sum;t=1; sum=0; n=1; s=1.0;while(n<=100){sum=sum+t;n=n+1;s=-s;t=s/n;}printf("sum=%10.6f\n",sum);}(2) 利用辗除法，直到b为0为止main(){ int p,r,n,m,temp;printf("input two integer n,m:");scanf("%d,%d",&n,&m);if(n<m){ temp=n;n=m;m=temp;}p=n*m;while(m!=0){r=n%m;n=m;m=r;}printf("greatest common divisor is:%d\n",n); //最大公约数printf("lease common multiple is:%d\n",p/n); //最小公倍数}(3) 采取逆向思维的方法，从后往前推断。

main(){int day,x1,x2;day=9;x2=1;while(day>0){ x1=(x2+1)*2; /*第一天的桃子数是第2天桃子数加1后的2倍*/ x2=x1;day--;}printf("the total is %d\n",x1);}(4)#include <stdio.h>main(){int i;long int n=1;for(i=1;i<=10;i++){n=n*i;printf(i%5==0?"%2d!=%-10ld\n":"%2d!=%-10ld",i,n); }}(5)main(){int m,s,i;for(m=2;m<1000;m++){ s=0;for(i=1;i<m;i++)if((m%i)==0) s=s+i;if(s==m){ printf("%d its factors are ",m);for(i=1;i<m;i++)if(m%i==0) printf("%d,",i);printf("\n");}}}(6)#include <stdio.h>main(){int n,i,j;scanf("%d",&n);for(i=1;i<=n;i++){ for(j=1;j<=n+i-1;j++)if(j<=n-i) printf(" ");else printf("*");printf("\n");}}(7)#include<math.h>main(){float x0,x1,x2,fx0,fx1,fx2;do{ printf("Enter x1 & x2:");scanf("%f,%f",&x1,&x2);fx1=x1*((2*x1-4)*x1+3)-6;fx2=x2*((2*x2-4)*x2+3)-6;}while(fx1*fx2>0);do{ x0=(x1+x2)/2;fx0=x0*((2*x0-4)*x0+3)-6;if((fx0*fx1)<0){ x2=x0;fx2=fx0;} else{ x1=x0;fx1=fx0;}}while(fabs(fx0)>=1e-5);printf("x=%6.2f\n",x0);}第6章1．选择题CCDCC AADBD2. 写出程序的运行结果(1) sum=6 (2) Max=9,row=1,col=0(3)1 02 1 03 2 1 0(4) -53、填空（1）i=j=k=0 、 i<4 、j<5、（2） s、 s[0],s[1] 、str,s[1]、s[2],str 4、编程题（1）#include <stdlib.h>main(){int a[12],count=0,i;randomize();for (i=0;i<12;i++)a=5+random(11);for(i=0;i<12;i++){printf("%5d",a);count++;if(count%4==0)printf("\n") ;}getch();}（2）main(){int a[5]={2,23,43,77,33};int max,min,i;long sum=0L;int count=0;float av;max=min=a[0];for(i=0;i<5;i++){sum+=a;if(a>max)max=a;if(a<min)min=a;}av=(float)sum/5;for(i=0;i<5;i++)if(a>av)count++;printf("max:%d\nmin:%d\nav:%f\ncount:%d",max,min,av,count);getch();}（3）main(){int score[30]={61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,85,89,90,33,44,55,91,92,93};int i,count90=0,count80=0,count70=0,count60=0;for(i=0;i<30;i++){printf("intput NO. %d student's score:",i+1);scanf("%d",score+i);}for(i=0;i<30;i++){if(score>=90){count90++;count80++;count70++;count60++;}else if(score>=80){count80++;count70++;count60++;}else if(score>=70){count70++;count60++;}else if(score>=60){count60++;}}printf("0~60:%d\n60~70:%d\n70~80:%d\n80~90:%d\n90~100:%d",30-count60,count60-count7 0,count70-count80,count80-count90,count90);printf("\n60 or higher:%d\n70 or higher:%d\n80 or higher:%d\n90 orhigher:%d\n",count60,count70,count80,count90);getch(); }（4）1、main(){char a[45];int i,j,k;for(i=0;i<45;i++)a=' '; for(i=0;i<5;i++){for(j=0;j<i;j++)a[9*i+j]=' ';for(k=0;k<5;k++)a[9*i+j+k]='*';}j=0;for(i=0;i<45;i++){printf("%c",a);j++;if(j%9==0)printf("\n"); }getch();}2、main(){char a[5][9];int i,j,k;for(i=0;i<5;i++)for(j=0;j<9;j++)a[j]=' ';for(i=0;i<5;i++){for(j=0;j<i;j++)a[j]=' ';for(k=0;k<5;k++)a[j+k]='*';}for(i=0;i<5;i++){for(j=0;j<9;j++)printf("%c",a[j]); printf("\n");}getch();}。