参考答案习题二(P33)一．单选题1.C2.B3.D4.C5.A6.D7.D8.B9.B 10.D 11.D 12.C 13.C . 15. A 14题最后一句应为printf("%f\n",d*y);结果为2.2二．填空题1. 182. int float double3. 10 114. 八十六十5. %三．阅读程序题1．10,10,9,102．j=1,i=2k=3,i=3j=3,i=2k=1,i=1习题三(P52)一．单选题1.D2.C3.D4.B5.A6.B7.C8.A9.C 10.B 11. -1,37777777777,4294967295 二．填空题5. L6. -1三．阅读程序题1. 6 6 6.00 6.002. x=127,x= 127,x=177,x=7fY=123.4567 , y= 123.46 , y=123.456703. 2,14. 12345. 4,36. -6,-6四．程序设计题1．#include "stdio.h"#include "math.h"main(){float a,b,c,d,x1,x2;a=2;b=-3;c=-5;d=b*b-4*a*c;x1=(-b+sqrt(d))/(2*a);x2=(-b-sqrt(d))/(2*a);printf("x1=%.2f,x2=%.2f\n",x1,x2);}2.#include <stdio.h>main(){ float a,v,s;scanf("%f",&a);v=a*a*a;s=6*a*a;printf("v=%.2f,s=%.2f\n",v,s);}3.#include <stdio.h>main(){ int a,b,c,t;scanf("%d%d%d",&a,&b,&c);printf("a=%d,b=%d,c=%d\n",a,b,c);t=c;c=b;b=a;a=t;printf("a=%d,b=%d,c=%d\n",a,b,c);}4.#include <stdio.h>main(){ char s1,s2;s1=getchar();s2=s1-32;printf("%c\n",s2);}习题四(P70)一．单选题1.C2.D3.D4.B5.A6.D7.D8.B9.C 10.A 11.B 12.D 13.passwarnerror .14.C 15. C 16.B 17. B 18. C二．填空题1. 非0 02. k==03. n%7==0 && n%8==0 else三．阅读程序题1. a=1,b=02. c=1四．程序设计题1.#include <stdio.h>main(){ int a,b;char c;printf("INPUT A+(-*/)B\n");scanf("%d%c%d",&a,&c,&b);switch(c){case'+':printf("%d+%d=%d\n",a,b,a+b);break;case'-':printf("%d-%d=%d\n",a,b,a-b);break;case'*':printf("%d*%d=%d\n",a,b,a*b);break;case'/':printf("%d/%d=%d\n",a,b,a/b);break;default:printf("INPUT ERROR!");}}2.#include <stdio.h>main(){ float x,y;scanf("%f",&x);if(x==0||x==2)y=0;else if(x>0) y=(x+1)/(x-2);else y=(x-1)/(x-2);printf("y=%f\n",y);}3.#include <stdio.h>main(){ int g;printf("请输入学生成绩:");scanf("%d",&g);printf("g=%d:",g);switch(g/10){case 10:printf("A\n");break;case 9:printf("B\n");break;case 8:printf("C\n");break;case 7:printf("D\n");break;case 6:printf("E\n");break;default:printf("F\n");}}4.#include <stdio.h>main(){ int x,n=0;scanf("%d",&x);if(x<=0||x>=10000)printf("Data Error!\n");else{if(x<10)n=1;else if(x<100)n=2;else if(x<1000)n=3;else n=4;}printf("n=%d\n",n);}习题五(P87)一．单选题1.B2.D3.C4.C5.B6.C7.D8.C9.A 10.D 11.B 12.B 13.B 14.D 15. C 二．填空题1. for语句while语句do-while语句2. a=14,y=263. k=14,n= -14. 395. s=196. 222227. 108. 79. 810. 5,5三．改错题应改为for（i=0;i<5;i++）j++;应改为int j=0;while(j<10){j++;i=j;} 注while(j<10)后不应有分号应改为while(j<10); 注while(j<10)后分号不能少s*=i;i++;应改为{s*=i;i++;}continue 应改为break四．程序设计题1.#include <stdio.h>main(){ int i,j,s=0;for(i=1,j=1;i<=100;i++,j=j*(-1))s=s+i*j;printf("s=%d\n",s);}1.（另一做法）#include<stdio.h>main(){int i,s;for(i=1,s=0;i<=100;i++)if(i%2==0)s=s-i;else s=s+i;printf ("%d\n",s);}2．#include <stdio.h>main(){ int i,j,s1=0,s2=0;for(i=0;i<10;i++){scanf("%d",&j);if(j>0)s1=s1+j;else s2=s2+j;}printf("s1=%d,s2=%d\n",s1,s2);}3．#include<stdio.h>main(){int i,s;for(i=6,s=0;i<=96;i=i+1)if(i%10==6||i/10==6)s=s+i;printf ("%d\n",s);}4．#include<stdio.h>main(){int i,a,b,c;for(i=100;i<=999;i++){a=(i%10);b=(i/10%10);c=(i/100);if(i==a*a*a+b*b*b+c*c*c)printf ("%d\n",i);}}5．#include <stdio.h>main( ){int i,j,k=0;for (i=1;i<=4;i++){for (j=1;j<=i;j++){k++;printf("%d",k%10);}printf("\n");}}6.#include <stdio.h>main( ){int i,j,k=0;for (i=-3;i<=3;i++){if(i<0)k=-i;else k=i;for(j=1;j<=k;j++)printf(" ");for(j=1;j<=7-2*k;j++)printf("*");printf("\n");}}习题六(P111)一．单选题1.D2.B3.C4.C5.C6.D7.A8.B二．填空题1. 20 0 192. 数组名3. 越界4. 65. j==k a[j][k]=1; a[j][k]=0;三．阅读程序题1． 6 5 43 2 12．aaabbbccc ddd3．2,2,1四．程序设计题1.#include<stdio.h>main(){ int a[4][4]={1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16}; int i,j,s=0;for(i=0;i<4;i++)for(j=0;j<4;j++)if(i==j||i+j==3)s+=a[i][j];printf("%d",s);}2.#include <stdio.h>{ char a[80];int i,j=5; /*假设删除位置为5*/gets(a);for(i=j-1;a[i]!='\0';i++)a[i]=a[i+1];a[i]='\0';puts(a);}3．#include <stdio.h>#include <string.h>main(){ char a[80];int i,j=5; /*假设插入位置为5*/char s='t'; /*假设插入字符为t*/gets(a);for(i=strlen(a);i>j;i--)a[i+1]=a[i];a[j]='t';puts(a);}4．#include<stdio.h>main(){ int a[3][5]={1,3,5,7,9,2,4,6,8,10,3,5,8,7,6}; int i,j,s1[3]={0},s2[5]={0};for(i=0;i<3;i++)for(j=0;j<5;j++)s1[i]+=a[i][ j];for(i=0;i<5;i++)for(j=0;j<3;j++)s2[i]+=a[ j][i];for(i=0;i<3;i++){for(j=0;j<5;j++)printf("%6d",a[i][j]);printf (" |%6d\n",s1[i]);}for(i=0;i<33;i++) printf("-");printf("\n");for(i=0;i<5;i++) printf("%6d",s2[i]);printf("\n");}5．#include<stdio.h>{ char s[3][80];int a=0,b=0,c=0,d=0,e=0,i,j;for(i=0;i<3;i++) gets(s[i]);for(i=0;i<3;i++)for(j=0;s[i][j]!='\0';j++)if(s[i][j]>='A'&&s[i][j]<='Z')a++;else if(s[i][j]>='a'&&s[i][j]<='z')b++;else if(s[i][j]>='0'&&s[i][j]<='9')c++;else if(s[i][j]==32)d++;else e++;printf("%3d%3d%3d%3d%3d",a,b,c,d,e);}习题七(P145)一．单选题1.A2.B3.C4.A5.C6.D7.C8.B9.B 10.C 11.D 二．填空题1. 该函数内局部2. 整型3. k<=breturn y;4. x[i]return (ave);fun(a,20)5. 1;add(n-1);add(n);6. n*f(n-1)0;f(i)三．阅读程序，写出运行结果1．10,20,302．643．84. hlo5. sum=55四．程序设计题1.#include <stdio.h>main(){float add(float, float), sub(float, float);float aver(float, float),a,b;scanf("%f,%f",&a,&b);printf("add=%f, sub=%f\n ", add(a,b), sub(a,b)); printf("aver =%f", aver(a,b));}float add(float x, float y) {return(x+y);}float sub(float x, float y) {return(x-y);}float aver(float x, float y) {return((x+y)/2);} 2.#include<stdio.h>main(){ int a,b,c,abmax(int,int);scanf("%d%d%d",&a,&b,&c);printf("max=%d\n",abmax(abmax(a,b),c)); }int abmax(int a,int b){if(a>b)return a;else return b;}3.#include <stdio.h>main(){float x,fun(float, int);int n;scanf("%f%d",&x,&n);printf("%f\n", fun(x,n));}float fun(float x, int n){float y;if(n==0)y=1;else y=x*fun(x,n-1);return y;}4.#include <stdio.h>main(){long f(int);int n,k;scanf("%d",&n);for(k=1;k<=n;k++)printf("%ld,",f(k));printf("\n");}long f(int n){long y;if(n<=2)y=1;else y=f(n-1)+f(n-2); return y;}5.#include <stdio.h>#include <string.h> main(){char a[50];int n;void fun(char x[ ],int n); gets(a);n=strlen(a); fun(a,n);puts(a);}void fun(char a[ ],int n) {int k,s;for(k=0;k<n/2;k++) {s=a[k];a[k]=a[n-k-1];a[n-k-1]=s;}}5. （另一做法）#include <stdio.h>#include <string.h> main(){char a[50];int n;void fun(char x[ ],int n); gets(a);n=strlen(a); fun(a,n);puts(a);}void fun(char a[ ],int n) {int k;char b[50];for(k=0;k<n;k++)b[n-1-k]=a[k];b[k]=a[k];strcpy(a,b);}6.#include <stdio.h>#define KK 100main(){char a[KK];long sjz(char a[]);int i=0,f1=0;printf("input a data:");gets(a);for(i=0;a[i]!='\0';i++){if(a[i]>='0'&&a[i]<='9'||a[i]>='A'&&a[i]<='F'||a[i]>='a'&&a[i]<='f') continue;else {f1=1;break;}}a[i]='\0';if(f1==1)printf("Data Error!\n");else printf("result is :%d\n",sjz(a));}long sjz(char a[]){long n=0,i;;for(i=0;a[i]!='\0';i++){if(a[i]>='0'&&a[i]<='9')n=n*16+a[i]-'0';if(a[i]>='A'&&a[i]<='F')n=n*16+a[i]-'A'+10;if(a[i]>='a'&&a[i]<='f')n=n*16+a[i]-'a'+10;}return n;}6.（另一做法）#include <stdio.h>#define KK 100main(){char str[KK],c;long sjz(char a[]);int i=0,f1=0;printf("input a data:");while((c=getchar())!='\n'&&i<KK){if(c>='0'&&c<='9'||c>='A'&&c<='F'||c>='a'&&c<='f')str[i++]=c;else f1=1;}str[i]='\0';if(f1==1)printf("Data Error!\n");else printf("result is :%d\n",sjz(str));}long sjz(char a[]){long n=0,i;;for(i=0;a[i]!='\0';i++){if(a[i]>='0'&&a[i]<='9')n=n*16+a[i]-'0';if(a[i]>='A'&&a[i]<='F')n=n*16+a[i]-'A'+10;if(a[i]>='a'&&a[i]<='f')n=n*16+a[i]-'a'+10;}return n;}习题八(P181) （注：无答案的题不在本课程讲授范围内）一．单选题1.D2.A3.C4.D5.C6.B7.C8.C9.C 13.D 14.B 15.A 16.C 17.A 二．填空题1. 指向取地址2. 2 +23. 286. *(p+5)7. ABCD A三．阅读程序题1．102．103．04. 3,65. 1 2 3 4四．程序填空题1．a,b,c或者&x,&y,&z max=*b或者max=y max=*c或者max=z2. ++ =*q ++ ++4. int *a,int *b b[j]=a[i] b[i++]5. *str+=3 *str>’z’&&*str<’a’||*str>’z’ a6. else 0 t[2*j+1]五．程序设计题1.#include <stdio.h>main(){int a[10],*p,*q,t;p=a;for(q=a;q<a+10;q++)scanf("%d",q);for(q=a;q<a+10;q++)printf("%5d",*q);printf("\n");q--;for(;p<q;p++,q--){t=*p;*p=*q;*q=t;}for(p=a;p<a+10;p++)printf("%5d",*p);printf("\n");}2.#include <stdio.h>#include <string.h>void main( ){ char a[50],*p1,*p2,t,n;gets(a);n=strlen(a);p1=a; p2=a+n-1;for(; p1<p2; p1++, p2--){t=*p1; *p1=*p2; *p2=t;}puts(a);}另一做法#include <stdio.h>main(){char str[20],*p=str;gets(str);while(*p)p++;p--;while(p>=str){printf("%c",*p);p--;}printf("\n");}3.#include <stdio.h>main(){int a[10],*p,*max,*min,t;for(p=a;p<a+10;p++)scanf("%d",p); for(p=a;p<a+10;p++)printf("%5d",*p); printf("\n");max=min=a;for(p=a+1;p<a+10;p++){if(*p>*max)max=p;if(*p<*min)min=p;}t=a[0];a[0]=*min;*min=t;t=a[9];a[9]=*max;*max=t;for(p=a;p<a+10;p++)printf("%5d",*p); printf("\n");}5.#include <stdio.h>int length(char *s){int n=0;while(*s){n++;s++;}return n;}main(){char str[20];int n;gets(str);n=length(str);printf("The string length is %d\n",n);}6.#include <stdio.h>main(){char str[81],*p=str,*q,t;gets(str);printf("The origenal string:\n");puts(str);for(p=str;*(p+1);p++)for(q=p+1;*q;q++)if(*q<*p){t=*p;*p=*q;*q=t;}printf("The result string:\n");puts(str);}习题九(P222) （注：无答案的题不在本课程讲授范围内）一．单选题1.D2.A3.B4.D 8.B 9.B 10.C二．填空题1. 结构体成员结构体指针指向2. 343. 224．ex三．阅读程序题1．92．10,x3．134. 46 40 415. 06. 3839。
