C语言程序设计答案曹计昌
第一章习题1.4原码：对于一个二进制数X，如果规定其最高位为符号位，其余各位为该数的绝对值，并且规定符号位值为0表示正，为1表示负，采用这种方式的二进制编码称为该二进制数X的原码。补码：正数的补码等于正数的原码，负数的补码为其原码除符号位不动外，其余各位变反再加1所得。反码：对于正数而言，反码与原码相同；对于负数而言，反码符号位的定义与原码相同，但需要将对应原码的数值位按位变反。1.5 和：10101010差：000100001.6 和 01073 差 -03371.7 和 0x1AABA差 -0x53201.8（251）10=（11111011）2=（373）8=（FB）161.10在16位机中，157补= 0000000010011101 -153补157-153=157+(-153)= (0000000010011101) 22=(0000000000000100) 2=(4) 101.14算法设计：用变量s存储累加和，k表示计数描述为：（1）定义变量s，k。（2）s清零，k赋初值1。（3）判断k<101？如果是，顺序执行（4）；否则转步骤（5）；（4）k加到累加和变量s中，k加1；转步骤（3）。（5）输出累加和s。（6）结束。 开始结束int s=0,k=1;k<101?s=s+k;k=k+1;输出sNY1.16 第二章习题2.2(1) x, +, +, y(2)-, 0xabL(3)2.89e+12L(4)”String+” FOO”(5)x, *, *, 2(6)”X?/”(7)a, ?, b(8)x, -, +=, y(9)intx, =, +, 10(10)”String”, “FOO” 2.3不是表识符的如下：4th 首字母为数字 sizeof关键字 x*y *不是字母、数字、下划线temp-2 -不是字母、数字、下划线isnt 不是字母、数字、下划线enum 关键字 2.4合法常数：.12 0.L 1.E-5 3.F 浮点型常量2L 33333 0377UL 0x9cfU 整型常量“a” “” 字符串常量45 a 字符常量 非法常数：必须用转义序列0x1ag 十六进制没有gE20 没有尾数部分18 要用八进制数xa 格式错误，可以是xa“34” 需要转义序列” 需要转义序列 2.5(1)int a, b=5;(2)double h;(3)int x=2.3; 0.3 会被截取。(4)const long y=1; 必须赋初值(5)float a= 2.5*g; g 没有定义。(6) int a=b=2; 在 turbo C 中编译出错：未定义的符号b在main函数中。 2.6 （1）4（2）0（3）1（4）6（5）8（6）0（7）3.00（8）1（9）108（10）0 2.7 答案不确定（1）a=b=c c未定义（2）正确（3）正确（4）正确（5）a*+-b 表达式缺值（6）a|bi 运算的操作数必须是整型，而i不是（7）i*j%a %运算的操作数必须是整型，而a不是（8）正确（9）正确（10）int（a+b） 应该改成（int）（a+b） 2.9（1）0（2）-2（3）65535（4）5（5）60（6）113（7）-2（8）-1（9）65532（10）3 2.10unsigned long encrypt(unsigned long x) unsigned long x0,x1,x2,x3,x4,x5,x6,x7; x0=(x & 0x0000000F) << 8; x1=(x & 0x000000F0); x2=(x & 0x00000F00) << 8; x3=(x & 0x0000F000); x4=(x & 0x000F0000) << 8; x5=(x & 0x00F00000); x6=(x & 0x0F000000) >> 24; x7=(x & 0xF0000000); return(x0|x1|x2|x3|x4|x5|x6|x7); 2.11#include<stdio.h>void main() unsigned long in;unsigned long a,b,c,d;scanf("%ld",&in);/in=1563;a=(in&0xff000000)>>24;b=(in&0x00ff0000)>>16;c=(in&0x0000ff00)>>8;d=in&0x000000ff;printf("%d.%d.%d.%d",a,b,c,d); 2.15(k >>8)& 0xFF00) | (p & 0x00FF)<<8) 2.16max=a>b?a>c?a:c:b>c?b:c;max=a > b ? (a > c) ? a : c):(b > c) ? b : c); 2.17X=y>>n 2.18（c>=0 && c<=9）? c 0 : c 2.19(a % 3 = 0) && (a % 10 = 5) ? a : 0;第三章习题3.1 函数原型是指对函数的名称、返回值类型、参数的数目和参数类型的说明。其规定了调用该函数的语法格式，即调用形式。putchar函数的原型为：int putchar(int c);puts函数的原型为： int puts(const char *s);printf函数的原型为：int printf(const char *format,);getchar函数的原型为:int getchar_r(void);gets函数的原型为:char * gets_r(char *s);scanf函数的原型为: int scanf(const char *format,);3.2 不同点： puts为非格式输出函数，printf为格式输出函数； puts函数的参数类型和数目一定(一个字符串)，printf函数的参数类型和数目不固定； puts函数输出后会自动换行，printf函数没有这一功能。 相同点：二者都向标准设备输出； 二者返回值类型都为int。3.3 x1=-1,177777,ffff,65535 x2=-3,177775,fffd,65533 y1=123.456703, 123.457,123.457,123.457 (注意对齐) y2=123.449997,1.23450e+02,123.45 x1(%4d)= -13.4 %c;%c;%f;%f;%lu;%d;%d;%d;%f;%Lf3.5 错误,运行提示为divide error 正确,结果为b 正确,结果为 * 正确 正确,但无法正常从结果中退出 正确 正确,结果为82,63 编译错误,提示 cannot modify a const object 正确 正确3.6 -6.70000 -6 177601 123 -2 03.8#include<stdio.h>void main() char c; c= getchar_r(); if(c>='0'&&c<='9')|(c>='A'&&c<='F')|(c>='a'&&c<='f') if(c>='0'&&c<='9') printf("%dn",c-'0'); else if(c>='A'&&c<='F') printf("%dn",c-'A'+10); else printf("%dn",c-'a'+10); else putchar(c); 3.9#include<stdio.h>void main() short num,high,low; printf("Please input a short number:n"); scanf("%hd",&num); low = 0x00ff & num; high = 0x00ff & (num >> 8); printf("The high byte is:%cn", high); printf("The low byte is:%cn", low); 3.10#include "stdafx.h" int main(int argc, char* argv) unsigned short int x; unsigned short int high,low; printf("input a integer:n"); scanf("%d",&x); high = (x>>12)&0x000f; low = (x<<12)&0xf000; x= x&0x0ff0; x=x|high|low; printf("%dn",x); return 0; 3.11 #include<stdio.h>void main()unsigned short int x,m,n;unsigned short int result;scanf("%hu%hu%hu",&x,&m,&n);result=(x>>(m-n+1)<<(15-n+1);printf("%hun",result); 3.12#include<stdio.h>void main() float f,c; scanf("%f",&f); c=(5*(f-32)/9; printf("%.0f(F)=%.2f(C)n",f,c);或者#include<stdio.h>void main()int f; float c; scanf("%d",&f); c=(5*(f-32)/9; printf("%d(F)=%.2f(C)n",f,c); 3.13#include <stdio.h>#define PI (3.1415926)int main(int argc, char* argv) double r, h; double s, v; printf("Please input the r and h."); scanf("%lf,%lf", &r, &h); s = 2 * PI * r * h + 2 * PI * r * r; v = PI * r * r * h; printf("s is %lf, v is %lf", s, v); return 0; 3.14#include "stdafx.h" int main(int argc, char* argv) char a4 = "编" printf("机内码：%x%xtn",a0&0xff,a1&0xff); printf("区位码：%xtn",a0&0xff<<8+a1&0xff-0x2020-0x8080); printf("国际码：%xtn",a0&0xff<<8+a1&0xff-0x8080); return 0;第四章习题4.1#include <stdio.h>void main(void)float a,b,c;printf("Please enter the score of A:n");scanf("%f",&a);printf("Please enter the score of B:n");scanf("%f",&b);printf("Please enter the score of C:n");scanf("%f",&c);if(a-b)*(a-c)<0) printf("A gets the score %.1f",a);if(b-a)*(b-c)<0) printf("B gets the score %.1f",b);if(c-a)*(c-b)<0) printf("C gets the score %.1f",c);4.3#include <stdio.h>int mdays(int y,int m) if (m=2) return (y%4=0 && (y%100=0 | y%400=0)?29:28; else if (m=4 | m=6 | m=9 | m=11) return 30; else return 31; main() int y,m,d,days; printf("Enter year:"); scanf("%d",&y); printf("Enter month:"); scanf("%d",&m); printf("Enter day:"); scanf("%d",&d); days=d; while(m>1)days+=mdays(y,m-1);m-; printf("%dn",days);4.4 if方法：#include "stdafx.h"#include <stdio.h>int main(int argc, char* argv) float x = 0; printf("input the salaryn"); scanf("%f",&x); if(x<0) printf("wrongn"); else if(x>0 && x<1000) printf("0n"); else if(x<2000) printf("%fn",x*0.05); else if(x<3000) printf("%fn",x*0.1); else if(x<4000) printf("%fn",x*0.15); else if(x<5000) printf("%fn",x*0.2); else printf("%fn",x*0.25); return 0; Case方法： #include "stdafx.h"#include <stdio.h>int main(int argc, char* argv) float x ; printf("input the salaryn"); scanf("%f",&x); int xCase = 0; xCase = (int)(x/1000.0); switch(xCase) case 0: printf("0n"); break; case 1: printf("%fn",x*0.05); break; case 2: printf("%fn",x*0.1); break; case 3: printf("%fn",x*0.15); break; case 4: printf("%fn",x*0.2); break; default: printf("%fn",x*0.25); return 0; 4.7#include "stdafx.h"#include <stdio.h>int main(int argc, char* argv) char *sa; char c; int i = 0,j = 0,k = 0; do c= getchar_r(); sai+ = c; while(c != 'r'); for(i=0;sai+1;i+) for(j = i+1;saj;j+) if( sai=saj && saj =' ') for(k=j;sak;k+) sak = sak+1; j-; for(k=0;sak;k+) printf("%2c",sak); return 0; 4.10#include <stdio.h>#define EPS 1e-5void main() int s=1; float n=1.0,t=1.0,pi=0; while(1.0/n>=EPS) pi=pi+t; n=n+2; s=s*(-1); t=s/n; pi=pi*4; printf("pi=%10.6fn",pi); 4.11#include<stdio.h>int main() int a,b,num1,num2,temp; printf("Input a & b:"); scanf("%d%d",&num1,&num2); if(num1>num2) temp=num1; num1=num2; num2=temp; a=num1; b=num2; while(b!=0) temp=a%b; a=b; b=temp; printf("The GCD of %d and %d is: %dn",num1,num2,a); printf("The LCM of them is: %dn",num1*num2/a);4.13#include "stdafx.h"#include <stdio.h>int Primes(int x);/判断素数函数int main(int argc, char* argv) int i,j; int num; for(num = 4;num<=100;num+) if(num%2 = 0) for(i=1;i<num;i+) for(j=1;j<num;j+) if(num = i+j) if(Primes(i) && Primes(j) printf("%d=%d+%dn",num,i,j); return 0; int Primes(int x) int i ; int n = 0; for(i = 1;i<=x;i+) if(x%i=0) n+; if(n=2) return 1; else return 0;4.17#include<stdio.h>void main(void) int c,i; for(i=1,c=32;c<=126;+i,+c) printf("%3d%-5c",c,c); if(!(i%8) printf("n"); 4.18#include "stdafx.h"#include <stdio.h>int main(int argc, char* argv) int x; int i,n,sum; printf("input 10 numbersn"); for(i = 0,n = 0,sum = 0;i<10;i+) scanf("%d",&x); if(x >0) sum+=x; n+; if(n) printf("numbers = %d,average = %fn",n,1.0*sum/n); return 0; 第五章习题5.5Extern和static存储类型的区别：Static型外部变量和extern型外部变量的唯一区别是作用域的限制。静态外部变量只能作用于定义它的文件，其他文件中的函数不能使用。Extern型外部变量的作用域可以扩大到整个程序的所有文件。Static和auto存储类型的区别：静态局部变量和自动变量有根本性的区别。由于静态局部变量在程序执行期间不会消失，因此，它的值有连续性。当退出块时，它的值能保存下来，以便再次进入块时使用，而自动变量的值在退出块时都丢失了。如果定义时静态局部变量有显示初始化，只在第一次进入时执行一次赋初值操作，而自动变量每次进入时都要执行赋初值操作。5.6不能。在C语言中，参数的传递方式是“值传递”，即把实参的值拷贝到参数的存储区中。因此，swap()函数交换的只是实参的本地拷贝，代表swap()实参的变量并没有被改变。5.7 6，125.10 #include <stdio.h>double sum_fac(int n) double s=0; int i; double fac=1.0; for(i=1;i<=n;i+) fac*=1.0/i; s+=fac; return s;void main(void) int n; printf("Please enter the integer n:"); scanf("%d",&n); printf("the sum is %lfn",sum_fac(n);5.17#include <stdio.h>void reverse() char ch= getchar_r(); if(ch!='n') reverse(); putchar(ch); int main() reverse(); printf("n"); return 0; 第六章习题6.1(1)正确(2)错误，不需要加“；”(3)错误，“ident”与“（”之间不能有空格(4)错误，宏名不能是关键字“void”(5)错误，将x*y改成(x）*(y) 6.4将会导致变量blue的重复定义 6.5(1)define NO 0(2)#include “common.h”(3)#line 3000(4)#undef TRUE #define TRUE 1(5)#if TRUE !=0#define FALSE 0#else #define FALSE 1#endif(6)#ifndef SIZE assert(0);#elseassert(SIZE<10&&SIZE>1);#endif(7)#define SQUARE_VOLUME(x) (x)*(x)*(x) 6.10#include <stdio.h>#define pi 3.1415926#define BALL_VOLUME(r) (4/3)*pi*(r)*(r)*(r)int main()int r;float v11;for(r=1;r<11;r+)vr=float(BALL_VOLUME(r);printf("r=%2d v=%.2fn",r,vr);return 0;第七章习题7.9#include<stdio.h>#include<graphics.h>#define g 10void main()char *buffer;int gdriver=DETECT,gmode,i,size;initgraph(&gdriver,&gmode,"c:tcbgi");setbkcolor(BLUE);setcolor(RED);setlinestyle(0,0,1);setfillstyle(1,5);circle(200,250,RED);size=imagesize(200,250,200,300);buffer=malloc(size);getimage_r(200,250,200,300,buffer);for(i=0;i<=10;i+)putimage(200,250+g*i*i/2,buffer,COPY_PUT);getch_r();closegraph(); 7.11#include<stdio.h>#define RAND_MAX 32767#define RAND 100int RandomInteger(int low,int high) int k; double d; d=(double)rand()/(double)RAND_MAX+1); k=(int)(d*(high-low+1); return(low+k);void main()long i;int n=0;int szWordRAND;char a="heads"char b="tails"srand(time(0);for(i=0;i<RAND;i+) szWordi=RandomInteger(0,1); if(szWordi=1) printf("n%s",a); n+; else printf("n%s",b); n=0; if(n=3) printf("nIt took %ld flips to get heads 3 consecutives times",i+1); break; 7.16 char *MonthName(int month);int MonthDays(int month,int year);int FirstDayOfMonth(int month,int year);int IsLeapYear(int year);enum weakSUNDAY ,MONDAY,TUESDAY,WEDNESDAY,THURSDAY,FRIDAY,SATURDAY; #include “caltools.h”char *MonthName(int month)Switch(month)Case 1: return(“January”);Case 2: return(“February”);Case 3: return(“March”);Case 4: return(“April”);Case 5: return(“May”);Case 6: return(“June”);Case 7: return(“July”);Case 8: return(“August”);Case 9: return(“September”);Case 10: return(“October”);Case 11: return(“November”);Case 12: return(“December”);Default : printf(“input error!n”); int MonthDays(int month,int year)Case 1:Case 3:Case 5:Case 7:Case 8:Case 10:Case 12: return(31);Case 4:Case 6:Case 9:Case 11: return(30);Case 1: return (IsLeapYear(year)?29:28); int FirstDayOfMonth(int month,int year)Int i;Long total=0;If(year=2000)For(i=1;i<month;i+)Total+=( MonthDays(i, 2000);Return(total%7+6)%7);)Else if(year>2000)For (i=2000;i<year;i+)Total+=(IsLeapYear(i)?366:365);For(i=1;i<month;i+)Total+=( MonthDays(i, year);Return(total%7+6)%7);)Else if(year=1999)For(i=12;i>month;i-)Total+=( MonthDays(i, 1999);Return(13-total%7)%7);ElseFor (i=1999;i<year;i-)Total+=(IsLeapYear(i)?366:365);For(i=12;i>month;i-)Total+=( MonthDays(i, year);Return(13-total%7)%7); int IsLeapYear(int year)Return ( !(year%4)&&(year%400) | !(year%400) ); #include <stdio.h>#include “caltools.h”Void main()Int month,year;Printf(“please input the month and year:”);Scanf(“%d%d” ,&month,&year);Printf(“the name of the month is %sn”, MonthName( month);Printf(“there are %d days in this month.n”, MonthDays( month,int year);Printf(“the first day of the month in this year is %d”, FirstDayOfMonth( month,year); 第八章习题8.4#include "stdafx.h"#include "malloc.h"#define N 65535 void DelSpace(char sa);int main(int argc, char* argv) char saN; char c; int i =0; do c = getchar_r(); if(c = 13) sai+ = 'n' else sai+ = c; while(c!=''); DelSpace(sa); int j = 0; while(1) if(saj = '') break; printf("%c",saj+); printf("/n"); return 0; void DelSpace(char sa) char *t1 = (char*)malloc(sizeof(sa); char *t2 = (char*)malloc(sizeof(sa); t1 = t2 = sa; while(*t1) *t2+ = *t1+; if(*(t2-1)=' ' && *t1=' ') t2-; 还有一个方法：void DelSpace(char sa,int n) char* tmpbuf = (char*)malloc(sizeof(sa)+1); int p1 = 0, p2 = 0; bool bSpace = false; while(p1 < n) if(bSpace && sap1 = ' ') p1+; else if(sap1 = ' ') bSpace = true; else bSpace = false; tmpbufp2+ = sap1+; strcpy(sa, tmpbuf); free( tmpbuf); 8.7#include "stdafx.h"#define NUM 100 struct stuInfo char name10; int mark;stuNUM; void scoreSort(stuInfo stu,int n);int main(int argc, char* argv) int n; printf("input the number of students:n"); scanf("%d",&n); printf("intput the name and scoren"); for(int i = 0;i<n;i+) scanf("%s",&stui.name); scanf("%d",&stui.mark); scoreSort(stu,n); int j = 0; while(j<n) printf("name:%s score:%dn",stuj.name,stuj.mark); j+; return 0; void scoreSort(stuInfo *stu,int n)/n为学生数 for(int i= 0;i<n;i+) for(int j =i;j<n;j+) if(stui.mark<stuj.mark) stuInfo temp; temp = stui; stui = stuj; stuj = temp; 8.9/ c84.cpp : Defines the entry point for the console application./ #include "stdafx.h"#define NUM 100 struct stuInfo char name10; int mark;stuNUM; void scoreSort(stuInfo stu,int n);int find(stuInfo *stu,int n,int score);int main(int argc, char* argv) int n; printf("input the number of students:n"); scanf("%d",&n); printf("intput the name and scoren"); for(int i = 0;i<n;i+) scanf("%s",&stui.name); scanf("%d",&stui.mark); scoreSort(stu,n); printf("input the socre you want to findn"); int score; scanf("%d",&score); int ifind =find(stu,n,score) ; if(ifind>=0) printf("name:%s score:%dn",stuifind.name,stuifind.mark); else printf("Not Find"); return 0; void scoreSort(stuInfo *stu,int n)/n为学生数 for(in
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