C++課后習題答案(電大,李寧主編)

1、C+語言程序設計習題參考答案 第一章 C+語言概述自測題 P2 1.1-1 C P8 1.2-1 形式參數(shù)表 1.2-2 main 1.2-3 ; 1.2-4 1.2-5 main 1.2-6 顯示器 輸出流 1.2-7 鍵盤 輸入流 1.2-8 頭文件 1.2-9 int f( );1.2-10 124 1.2-11 1.2-12 1.2-13 1.2-14 1.2-15 1.2-16 1.2-17 ABCFG 1.2-18 D1.2-19 D P11 1.3-1 OBJ 1.3-2 source.cpp習題一 （P12）1-1 1C 2類型修飾符 3main 4語句以分號（；）結束 5 6

2、 8.h 9source.obj 10Main 11char * Hi(const char *); 12331-2 1 2 3 4 5 6 7 81-3 1ABFI 2D 3ABCD 4B1-4 # include void main( ) cout ”C+語言程序設計”endl; 1-5 # include void main() int i,j,k;cout ijk;cout endli”+”j”+”k”=”i+j+ky+3 2.8-2 x!=3 & x=-3 2.8-3 B2.8-4 C 2.8-5 BC 2.8-6 AD2.8-7 D 2.8-8 C 2.8-9 A 2.8-10 C

3、D 2.8-11 D 2.8-12 B 2.8-13 !isMale Age=55 Age=50 & isMale Age100?100:0); 2. 7 3. 17 4. D:MyDirMyFile.Dat 5. C F 6. 48+n U 或 char(48+n) U 或 n+0 U 7. Jun thisMonth+1 ( 說明：VC+不支持枚舉數(shù)據(jù)參加算術運算，此例無法編譯)8. ( 說明：題目有錯，cin m; 編譯出錯，C+不支持枚舉數(shù)據(jù)輸入)9. 12.3456 9.87653e3 10. 3.66667 4.0 411. 57 45.0 G 12. 92 13. Whats y

4、our name? 14. 7715. 2 44 3 16. 7 4 317. 3 1 18. 6 1019. 3 7 20. 5 221. f=+p+5; 22. f=p-5;23. x+y=3 24. x=-525. a*a*a+3*a*a*a*b+3*a*b*b+b*b*b 26. 1.0/2*a*sqrt(b+2*c)/5) 27. IsMale Age30 Age=50|IsMale 2-3 2-4 1. B 2. A 3. AB 4. B 5. A 6. ABCD 7. CEFHI 8. CEFGHJ 9. C 10. C 11. A 12. AB 13. C2-5 / P50 習

5、題2-5 # include # include void main() double a,r; cout endla; r=1.0/2*a*sqrt(10+2*sqrt(5)/5); cout endl正五邊形外接圓的半徑：rendl;2-6 / P50 習題2-6# include # include void main()double a,b,c,area,s;cout endlabc;s=(a+b+c)/2;area=sqrt(s*(s-a)*(s-b)*(s-c); cout endl三角形的面積：areaendl; 2-7 / P50 習題2-7# include # includ

6、e void main()double x1,y1,z1,x2,y2,z2,d;cout endlx1y1z1;cout endlx2y2z2;d=sqrt(x2-x1)*(x2-x1)+(y2-y1)*(y2-y1)+(z2-z1)*(z2-z1); cout endl兩點間的距離：dendl;第三章 C+程序的流程控制自測題 P52 3.1-1 順序 條件分支 循環(huán) 只有一個入口和一個出口 P65 3.2-1 false 3.2-2 AB 3.2-3 B 3.2-4 t=x; x=y; y=t; 3.2-5 if (!OK) y=1; else if (READY) y=-1; else

7、y=0;3.2-6 1 2 3 n-1 3.2-7 XYZ 3.2-8 if (k=1 | k=2 | k=3) cout ”A”;else if (k=4 | k=5) cout ”B”; else cout =1 & k=3) cout =4 & k=5) cout ”B”; else cout ”C”;3.2-9 switch (x) case 0: case 1: case 2: cout ”X”; break; case 20: case 21: case 22: cout ”Y”; break; default : cout ”C”; break; ;3.2-10 ABD 3.2-

8、11 AD 3.2-12 BC 3.2-13 BCD P78 3.3-1 28 3.3-2 21 3.3-3 for ( int i=10; i100; i+ ) cout ”P”; 3.3-4 117 3.3-5 i=0; while (i10) cout 0; i- ) cout i; 習題三 （P82）3-1 1. y z或 z y 2. true 3. A 4. A 5. x+=y; y=x-y; x-=y; 6. y=OK?(READY?-1:0):1; 7. ABC 8. XYZ 9. ABC 10. 22 11. 23 12. for (int i=100; i; i-) cou

9、t P; 13. 4614. if (k=1 | k=2 ) cout A; else if ( k=3 | k=4 | k=5 ) cout B;else cout =1 & k=2 ) cout =3 & k=5 ) cout B;else cout C; 15. switch (x) case 1: case 2: case 3: cout X; break; case 19: case 20: case 21: case 22: cout Y; break; default : cout Z; break; 16. 133-2 1. ABC 2. ABD 3. C 4. ACD3-3

10、/ P84 習題3-3# include void main()int weekday;cout endlweekday;if (weekday=0)cout Sundayendl;else if (weekday=1)cout Mondayendl;else if (weekday=2)cout Tuesdayendl;else if (weekday=3)cout Wednesdayendl;else if (weekday=4)cout Thursdayendl;else if (weekday=5)cout Fridayendl;else if (weekday=6)cout Satu

11、rdayendl;else cout 表示星期幾的數(shù)必須在0-6之間！endl;3-4 / P84 習題3-4# include void main()int a,b,c,d,max;cout abcd;max=a;if (maxb) max=b;if (maxc) max=c;if (maxd) max=d;cout endl;cout 最大的數(shù)是：maxendl;3-5 / P84 習題3-5# include void main()int a,b,c,d,temp;cout abcd;cout 排序前：a b c db) temp=a; a=b; b=temp;if (ac) temp=

12、a; a=c; c=temp;if (ad) temp=a; a=d; d=temp;/ 求第二小數(shù)存入bif (bc) temp=b; b=c; c=temp;if (bd) temp=b; b=d; d=temp;/ 求第三小的數(shù)存入cif (cd) temp=c; c=d; d=temp;cout 排序后：a b c dendl;3-6 / P84 習題3-6# include void main()cout endl |; / 以下3行顯示頂部表欄 int i=1;while (i10)cout setw(3)i;i+;cout endl-+-;i=1;while (i10) / 乘數(shù)

13、從1 循環(huán)到9cout endlsetw(2)i|;int j=1;while (j10)cout setw(3)i*j; / 被乘數(shù)從1 循環(huán)到9j+;i+; coutendlendl;3-7 / P84 習題3-7# include void main()int a=1,b=2; double s=0,p;for (int i=1; i=20; i+)p=(double)b/a;s+=p;b+=a; / 產(chǎn)生分子a=b-a; / 產(chǎn)生分母cout 2/1+3/2+5/3+8/5+.=sendl;3-8 / P84 習題3-8# include # define N 15void main(

14、)int n; long double s=0.0L,fact=1.0L;for (n=1; n=N; n+) fact*=n; / 計算n! s+=fact;cout 1!+2!+.+N!=sendl;3-9 / P84 習題3-9 / 方法一# include void main()int n1=1,n2=1,n=n1+n2,couter=2; / n1，n2相鄰二項的分母，cout統(tǒng)計項數(shù) double s=2.0,s0;while (s0=1.0/n)=0.000001)s+=s0;n1=n2;n2=n;n=n1+n2;couter+; coutendlendl; cout 累加和：s

15、endl; cout 累加項數(shù)：couterendl;/ 方法二# include void main()int n=2,d=1,k=2; / k統(tǒng)計項數(shù) double s=2.0,s0;while (s0=1.0/n)=0.000001)s+=s0;n+=d;d=n-d;k+; coutendlendl; cout 累加和：sendl; cout 累加項數(shù)：kendl;3-10 / P84 習題3-10# include void main()for (int i=1; i=6; i+)cout endl;int j;for (j=1; ji; j+) cout ;for (j=1; j=1

16、3-i-i; j+) cout *;cout endlendl;3-11 / P81 習題3-11# include void main() cout setw(6)*; / 輸出頂* for (int i=0; i4; i+)cout endl;int j;for (j=0; j4-i; j+) / 輸出載邊空格cout ;cout *; / 輸出左*for (j=0; ji+i+1; j+) / 輸出中間空格cout ;cout *; / 輸出右*cout endl*;cout endlendl;3-12 / P81 習題3-12# include void main() int i;co

17、ut endl |; for (i=0; i=9; i+)cout setw(6)i;cout endl-+;for (i=0; i=10; i+) cout -;for (i=0; i=9; i+)cout endlsetw(5)i|;for (int j=0; j=9; j+)cout setw(6)(i*10+j)*(i*10+j);cout endlendl;3-13 / P81 習題3-13# include # include void main() double x;cout x;int i=1;double n=-x*x,d=1.0*2.0,s=1.0,s0;while (fa

18、bs(s0=n/d)=0.000001)s+=s0;i+;n*=(-x*x);d*=(i+i)*(i+i-1);cout 累加求值 COS(x)=sendl;cout 標準函數(shù) COS(x)=cos(x)endl;cout endlendl;第四章 數(shù) 組自測題 P93 4.1-1 (3,6,9,0,0) (0) (4) 4.1-2 (9,6,3) (0) (2)4.1-3 (100) (0) (99) 4.1-4 (ACD)4.1-5 int j=9 ， j=0 ，-Tj 4.1-6 0 ，j10 ，j+ ，s+=TjP99 4.2-1 (5) (3) (15) (4) (2) 4.2-2

19、(2) (4) (8) (1) (3) (1,2,3,4)4.2-3 (3) (3) (9) (1,2,0,5,0,0,6,7,8) 4.2-4 int g5=1,1,2,1,2,3,1,2,3,4,1,2,3,4,5;4.2-5 0 ， 6 ， i+ ， hii 4.2-6 0 ， 5 ， i+ ， int j=0 ， j3 ， mij4.2-7 BCDP105 4.3-1 XABCD 4.3-2 net ， internet4.3-3 strcpy(s3,s1); strcpy(s1,s2); strcpy(s2,s3);4.3-4 strcat(s3,s1); strcat(s3,s2)

20、 ; 或 strcat(strcat(s3,s1),s2)4.3-5 if ( !strcmp(s1,s2) ) cout s1endls20) cout s1endl;else cout s20 ) cout s1endl; else if (strcmp(s1,s2)0) cout s2endl; else cout s1endls2endl;或 if ( strcmp(s1,s2)0 ) cout s20) cout s1endl; else cout s1endls2endl;4.3-6 D 4.3-7 BCD習題四 （P107）4-1 1. ( 3,6,9,12 ) ( 0 ) (

21、3 ) 2. ( 9,6,3,0,0,0 ) ( 0 ) ( 5 ) 3. ( 50 ) ( 0 ) ( 49 ) 4. ( int j=0 ) ( j+=2 ) ( aj )5. ( 0 ) ( j=0 ) ( j18 ) ( s+=s0j ) ( /= ) (說明：題目的“并用s保存”改為“并用s0保存”) 6. ( 4 ) ( 11 ) ( 44 ) ( 3 ) ( 10 ) 7. ( 3 ) ( 5 ) ( 15 ) ( 2 ) ( 4 ) ( 1,2,3,0,0 , 5,6,0,0,0 , 8,0,0,0,0 ) 8. ( 4 ) ( 3 ) ( 12 ) ( 1,2,0,5,0,0

22、,6,7,8,0,0,0 ) 9. ( int g55=1,2,3,4,5,1,2,3,4,1,2,3; 10. ( int i=0 ) ( i8 ) ( hii ) 11. ( 0 ) ( 5 ) ( i+ ) ( int j=0 ) ( j3 ) ( m4-ij ) 12. ( “ABCD” ) 13. ( net ) ( in ) 14. ( aaabbbbccccc , bbbbccccc , ccccc ) 15. ( aaa , cccccaaa , ccccc )16. ( abc , abf , abcdabf )4-2 1. BCD 2. AB 3. CD 4. AC4-3

23、/ P109 習題4-3 # include # define SIZE 10void main()int aSIZE; int temp,i,max,min;cout 輸入SIZEa0;max=min=0; / 存放最大數(shù)和最小數(shù)的下標for (i=1; iai;if (aiamax) max=i; / 保存當前最大數(shù)的下標if (aiamin) min=i; / 保存當前最小數(shù)的下標cout endl交換前：;for (i=0; iSIZE; i+)cout ai ;temp=a0; a0=amax; amax=temp; / 最大數(shù)存首元素temp=aSIZE-1; aSIZE-1=am

24、in; amin=temp; / 最小數(shù)存末元素 cout endl交換后：;for (i=0; iSIZE; i+)cout ai ;cout endlendl;4-4 / P109 習題4-4 方法一：# include void main()int a=23,25,13,68,3,44,11,7,55,36;const int SIZE=sizeof(a)/sizeof(a0); / 數(shù)組a的元素個數(shù) int temp,i;cout endl處理前：;for (i=0; iSIZE; i+)cout ai ;for (i=0; i5; i+) / 找前5大數(shù)之一int k=i,j; /

25、k保存大數(shù)的下標for (j=5; jak) k=j; temp=ai; ai=ak; ak=temp; / 交換cout endl處理后：;for (i=0; iSIZE; i+)cout ai ;cout endlendl;方法二：/ P109 習題4-4 # include void main()int a=23,25,13,68,3,44,11,7,55,36;const int SIZE=sizeof(a)/sizeof(a0); / 數(shù)組a的元素個數(shù) int temp,i;cout endl處理前：;for (i=0; iSIZE; i+)cout ai ;for (i=0; i5

26、; i+) / 用選擇排序法排前5個數(shù)為大數(shù)int k=i,j; / k保存當前最大數(shù)的下標for (j=i+1; jak) k=j; temp=ai; ai=ak; ak=temp; / 交換cout endl處理后：;for (i=0; iSIZE; i+)cout ai ;cout endlendl;4-5 / P109 習題4-5# include # define SIZE 20void main()int aSIZE,i; cout endl請輸入SIZE個正整數(shù): ;for ( i=0; iai;while (ai=0);cout endl處理前: ;for (i=0; iSIZ

27、E; i+) cout ai ;cout endl;int j=0; / j為奇數(shù)存放下標 for (i=0; iSIZE; i+)if ( ai%2 ) / 條件成立，表示ai為奇數(shù)int temp=ai; ai=aj; aj=temp;j+; / 下一個奇數(shù)存放位置cout endl處理后: ;for (i=0; iSIZE; i+) cout ai ;cout endlendl;4-6 / P109 習題4-6# include void main() int a=23,25,13,68,3,44,11,7,55,36;const int SIZE=sizeof(a)/sizeof(a0

28、); / 數(shù)組a的元素個數(shù) int i,number; cout endlnumber;cout endlendl整數(shù)序列: ;for (i=0; iSIZE; i+) / 顯示數(shù)組元素 cout ai ;cout endlendl輸入數(shù): number的序號: ; for (i=0; iSIZE & ai!=number; i+) ; / 查找 cout (iSIZE)?i+1:0)endl; / 表達式中條件成立，表示找到cout endl;4-7 / P109 習題4-7# include # define SIZE 5void main() int aSIZESIZE;int i,j,

29、sum=0; cout endl請輸入SIZE行SIZE列整型數(shù)組: endl;for (i=0; iSIZE; i+)for (j=0; jaij;cout endlendlSIZE行SIZE列整型矩陣: ;for (i=0; iSIZE; i+) / 顯示二維數(shù)組元素cout endl;for (j=0; jSIZE; j+) cout setw(4)aij;for (i=0; iSIZE; i+)for (j=0; jSIZE; j+)if (i=0 | j=0 | i=SIZE-1 | j=SIZE-1)sum+=aij;cout endlendl矩陣四周元素的合計值: sumendl

30、endl;4-8 / P109 習題 4-8# include # include # define SIZE 10void main()double dataSIZESIZE;int i,j,size;cout size;if (size10)cout 行列式的階數(shù)要求在 1-10 之間.endl;return;/ 輸入行列式cout 請輸入size行size列的行列式：endl;for (i=0; isize; i+)for (j=0; jdataij;/ 輸出行列式cout endlendlsize行size列的行列式：endl; for (i=0; isize; i+)cout end

31、l;for (j=0; jsize; j+)cout setw(10)dataij; cout endl;/ 調(diào)用函數(shù)grmdet()計算行列式的值double grmdet(double aSIZE,int size); cout endlsize行size列的行列式的值為：;cout grmdet(data,size)endl;/ 計算行列式的值函數(shù)。以下函數(shù)定義參閱1982年12月第1版上海教育出版社出版/ 上海計算技術研究所編電子計算機算法手冊第295頁算法double grmdet(double aSIZE,int size)int i,j,k,n;double p,t,u;double mSIZE;for (i=0; isize; i+) u=0.0;for (j=0; ju) ) u=abs(aij);if (u1.0E-18) return 0.0;mi=u;if (u!=1)for (j=0; jsize; j+)aij/=u;p=1;for (k=0; ksize-