cprimerplus第編程練習答案已

1、PE 2-1/* Programming Exercise 2-1 */ #include int main(void) printf(Gustav Mahlern); printf(GustavnMahlern); printf(Gustav ); printf(Mahlern); return 0;PE2-3/* Programming Exercise 2-3 */ #include int main(void) int ageyears; /* age in years */ int agedays; /* age in days */* large ages may require

2、the long type */ ageyears = 101; agedays = 365 * ageyears;printf(An age of %d years is %d days.n, ageyears, agedays); return 0; PE2-4/* Programming Exercise 2-4 */#include void jolly(void); void deny(void); int main(void) jolly(); jolly(); jolly(); deny(); return 0; void jolly(void)printf(For hes a

3、jolly good fellow!n);void deny(void) printf(Which nobody can deny!n);PE2-6/* Programming Exercise 2-6 */#include int main(void) int toes;toes = 10; printf(toes = %dn, toes);printf(Twice toes = %dn, 2 * toes); printf(toes squared= %dn, toes * toes); return 0;/* or create two more variables, set them

4、to 2 * toes and toes * toes */PE 2-8/* Programming Exercise 2-8 */ #include void one_three(void); void two(void); int main(void)printf(starting now:n); one_three(); printf(done!n); return 0;void one_three(void)printf(onen); two();printf(threen); void two(void) printf(twon);Chapter 3 Programming Exer

5、cisesPE 3-2/* Programming Exercise 3-2 */ #include int main(void) int ascii;printf(Enter an ASCII code: ); scanf(%d, &ascii);printf(%d is the ASCII code for %c.n, ascii, ascii); return 0; PE 3-4/* Programming Exercise 3-4 */ #include int main(void) float num;printf(Enter a floating-point value: ); s

6、canf(%f, &num); printf(fixed-point notation: %fn, num); printf(exponential notation: %en, num); printf(p notation: %an, num); return 0;PE 3-6/* Programming Exercise 3-6 */ #include int main(void) float mass_mol = ; /* mass of water molecule in grams */ float mass_qt = 950; /* mass of quart of water

7、in grams */ float quarts; float molecules;printf(Enter the number of quarts of water: ); scanf(%f, &quarts); molecules = quarts * mass_qt / mass_mol;printf(%f quarts of water contain %e molecules.n, quarts, molecules); return 0; Chapter 4 Programming ExercisesPE 4-1/* Programming Exercise 4-1 */ #in

8、clude int main(void) char fname40; char lname40;printf(Enter your first name: ); scanf(%s, fname); printf(Enter your last name: ); scanf(%s, lname); printf(%s, %sn, lname, fname); return 0;PE 4-4/* Programming Exercise 4-4 */ #include int main(void) float height; char name40;printf(Enter your height

9、 in inches: ); scanf(%f,&height); printf(Enter your name: ); scanf(%s, name);printf(%s, you are %.3f feet talln, name, height / ; return 0;PE4-7/* Programming Exercise 4-7 */#include #include int main(void) float ot_f = / ; double ot_d =/ ; printf( float values: );printf(%.4f %.12f %.16fn, ot_f, ot_

10、f, ot_f); printf(double values: );printf(%.4f %.12f %.16fn, ot_d, ot_d, ot_d); printf(FLT_DIG: %dn, FLT_DIG); printf(DBL_DIG: %dn, DBL_DIG); return 0;Chapter 5 Programming ExercisesPE5-1/* Programming Exercise 5-1 */ #include int main(void) const int minperhour = 60; int minutes, hours, mins;printf(

11、Enter the number of minutes to convert: ); scanf(%d,&minutes); while (minutes 0 ) hours = minutes / minperhour;mins = minutes % minperhour;printf(%d minutes = %d hours, %d minutesn, minutes, hours, mins); printf(Enter next minutes value (0 to quit): ); scanf(%d, &minutes);printf(Byen); return 0;PE5-

12、3/* Programming Exercise 5-3 */ #include int main(void) const int daysperweek = 7; intdays, weeks, day_rem; printf(Enter the number of days: );scanf(%d, &days); while (days 0) weeks = days / daysperweek;day_rem = days % daysperweek; printf(%d days are %d weeks and %d days.n, days,weeks, day_rem); pr

13、intf(Enter the number of days (0 or less to end): ); scanf(%d, &days);printf(Done!n); return 0;PE 5-5/* Programming Exercise 5-5 */ #include int main(void) /* finds sum of first n integers */ int count, sum;int n;printf(Enter the upper limit: ); scanf(%d,&n); count = 0; sum = 0; while (count+ n) sum

14、 = sum + count; printf(sum = %dn, sum); return 0;PE5-7/* Programming Exercise 5-7 */ #include void showCube(double x);int main(void) /* finds cube of entered number */ double val;printf(Enter a floating-point value: );scanf(%lf, &val); showCube(val); return 0; void showCube(double x)printf(The cube

15、of %e is %e.n, x, x*x*x );ExercisesChapter 6 ProgrammingPE6-1/* */* this implementation assumes the character codes */ /* are sequential, as they are in ASCII. */ #include #define SIZE 26 int main( void ) char lcaseSIZE; int i;for (i = 0; i SIZE; i+) lcasei= a + i; for (i = 0; i SIZE; i+) printf(%c,

16、 lcasei); printf(n);return 0;PE6-3/* */* this implementation assumes the character codes */ /* are sequential, as they are in ASCII. */ #include int main( void ) char let = F; charstart; char end;for (end = let; end = A; end-)for (start = let; start = end; start-) printf(%c, start); printf(n); retur

17、n0;PE6-6/* */ #include intmain( void ) int lower, upper, index; intsquare, cube;printf(Enter starting integer: ); scanf(%d, &lower); printf(Enter ending integer: ); scanf(%d, &upper);printf(%5s %10s %15sn, num, square, cube); for (index = lower; index = upper; index+) square = index * index;cube = i

18、ndex * square;printf(%5d %10d %15dn, index, square, cube);return 0;PE 6-8/* */ #include int main( void ) double n, m; double res;printf(Enter a pair of numbers: );while (scanf(%lf %lf, &n, &m) = 2)res = (n - m) / (n * m);printf(%.3g - %.3g)/(%.3g*%.3g) = %.5gn, n, m, n, m, res); printf(Enter next pa

19、ir (non-numeric to quit): );return 0;PE 6- 11/* */#include #define SIZE 8int main( void ) int valsSIZE; int i;printf(Please enter %d integers.n, SIZE); for (i = 0;i = 0; i-)printf(%d , valsi); printf(n);return 0;PE 6- 13/* */* This version starts with the 0 power */ #include #define SIZE 8 int main(

20、 void )int twopowsSIZE; int i;int value = 1; /* 2 to the 0 */for (i = 0; i SIZE; i+) twopowsi = value;value *= 2; i =0; do printf(%d , twopowsi);i+; while (i SIZE); printf(n); return 0;PE 6- 14/* */ /* Programming Exercise 6-14 */ #include #define SIZE 8 int main(void) double arrSIZE; double arr_cum

21、ulSIZE; int i;printf(Enter %d numbers:n, SIZE);for (i = 0; i SIZE; i+) printf(value #%d: , i + 1); scanf(%lf, &arri); /* or scanf(%lf, arr + i); */ arr_cumul0 = arr0; /* set first element */ for (i = 1; i SIZE; i+)arr_cumuli = arr_cumuli-1 + arri;for (i = 0; i SIZE; i+) printf(%8g , arri); printf(n)

22、; for (i = 0; i SIZE; i+) printf(%8g , arr_cumuli); printf(n); return 0;PE 6- 16/* */ #include #define RATE_SIMP #define RATE_COMP #define INIT_AMT int main( void )double daphne = INIT_AMT; double deidre = INIT_AMT; int years = 0;while (deidre = daphne) daphne += RATE_SIMP * INIT_AMT; deidre += RATE

23、_COMP * deidre;+years; printf(Investment values after %d years:n, years); printf(Daphne: $%.2fn, daphne); printf(Deidre: $%.2fn, deidre); return 0;Chapter 7 Programming Exercises PE7-1/* Programming Exercise 7-1 */ #include int main(void) char ch; int sp_ct = 0; int nl_ct = 0; int other = 0;while (c

24、h = getchar() != #) if (ch = ) sp_ct+;else if (ch = n)nl_ct+;elseother+;printf(spaces: %d, newlines: %d, others: %dn, sp_ct, nl_ct, other); return 0;PE 7-3/* Programming Exercise 7-3 */ #include int main(void) int n; double sumeven = ;int ct_even = 0; double sumodd= ; int ct_odd = 0;while (scanf(%d,

25、 &n) = 1 & n != 0)if (n % 2 = 0)sumeven += n;+ct_even;else : putchar(!);+ct1; break;case ! : putchar(!);putchar(!); +ct2; break; default : putchar(ch); printf(%d replacement(s) of . with !n, ct1); printf(%d replacement(s) of ! with !n, ct2);return 0;PE7-7f; taxes: $%.2f; net: $%.2fn, gross, taxes, n

26、et);return 0;PE7-9/* Programming Exercise 7-9 */ #include #include int main(void)int limit; int num; int div;bool numIsPrime; n); for (num = 2; num =limit; num+)for (div = 2, numIsPrime = true; (div * div) = num; div+) if (num % div = 0)numIsPrime = false; if (numIsPrime)printf(%d is prime.n, num);p

27、rintf(Enter a positive integer (q to quit): );printf(Done!n);return 0;PE7- 11/* */* Programming Exercise 7-11 */#include #include int main(void)const double price_artichokes = ; const double price_beets = ; const double price_carrots = ;const double DISCOUNT_RATE = ; const double under5= ; const dou

28、ble under20 = ; const double base20= ; const double extralb = ;char ch;double lb_artichokes = 0; doublelb_beets = 0; double lb_carrots = 0; double lb_temp; double lb_total;double cost_artichokes; double cost_beets; double cost_carrots;double cost_total; double final_total; double discount;double shi

29、pping;printf(Enter a to buy artichokes, b for beets, ); printf(c for carrots, q to quit: ); while (ch = getchar() != q & ch != Q) if (ch = n)continue; while (getchar() != n)continue; ch = tolower(ch);switch (ch) case a : printf(Enter pounds of artichokes: );scanf(%lf, &lb_temp);lb_artichokes += lb_t

30、emp;break;case b : printf(Enter pounds of beets: ); scanf(%lf, &lb_temp); lb_beets += lb_temp; break;case c : printf(Enter pounds of carrots: ); scanf(%lf, &lb_temp); lb_carrots += lb_temp; break;default : printf(%c is not a valid choice.n, ch);printf(Enter a to buy artichokes, b for beets, ); print

31、f(c for carrots, q to quit: );cost_artichokes = price_artichokes * lb_artichokes; cost_beets = price_beets * lb_beets; cost_carrots = price_carrots * lb_carrots; cost_total = cost_artichokes + cost_beets + cost_carrots; lb_total = lb_artichokes + lb_beets + lb_carrots; if (lb_total = 0) shipping = ;

32、 else if (lb_total shipping = under5; else if (lb_total discount = DISCOUNT_RATE * cost_total; else discount = ;final_total = cost_total + shipping - discount; printf(Your order:n); printf(%.2f lbs of artichokes at $%.2f per pound:$ %.2fn, lb_artichokes, price_artichokes, cost_artichokes); printf(%.

33、2f lbs of beets at $%.2f per pound: $%.2fn,lb_beets, price_beets, cost_beets);printf(%.2f lbs of carrots at $%.2f per pound: $%.2fn, lb_carrots, price_carrots, cost_carrots); printf(Total cost of vegetables: $%.2fn, cost_total); if (cost_total 100)printf(Volume discount: $%.2fn, discount); printf(Sh

34、ipping: $%.2fn, shipping); printf(Total charges: $%.2fn, final_total); return 0; Chapter 8 Programming ExercisesPE 8-1/* Programming Exercise 8-1 */ #include int main(void) int ch; int ct = 0; while (ch = getchar() != EOF) ct+;printf(%d characters readn, ct);return 0;PE8-3/* Programming Exercise 8-3

35、 */* Using eliminates need to assume consecutive coding */ #include #include int main(void) int ch; unsigned long uct = 0; unsigned long lct = 0; unsigned long oct = 0;while (ch = getchar() != EOF) if (isupper(ch) uct+; else if (islower(ch) lct+; else oct+;printf(%lu uppercase characters readn, uct)

36、; printf(%lu lowercase characters readn, lct); printf(%lu other characters readn, oct);return 0;/* or you could use if (ch = A &ch = a & ch = z) lct+;else oct+;*/PE8-5/* Programming Exercise 8-5 */* - an improved number-guesser */* but relies upon truthful, correct responses */ #include #include int

37、 main(void) int high = 100; int low = 1; int guess = (high + low) / 2; char response;printf(Pick an integer from 1 to 100. I will try to guess ); printf(it.nRespond with a y if my guess is right, with); printf(na h if it is high, and with an l if it is low.n); printf(Uh.is your number %d?n, guess);w

38、hile (response = getchar() != y) /* get response */if (response = n) continue;if (response != h & response != l)printf(I dont understand that response. Please enter h forn); printf(high, l for low, or y for correct.n); continue;if (response = h) high = guess - 1; else if (response = l)low = guess +

39、1; guess = (high + low) / 2;printf(Well, then, is it %d?n, guess);printf(I knew I could do it!n); return 0; PE 8-7/* Programming Exercise 8-7 */#include #include #include #define BASEPAY1 */ switch (response)case a: pay = BASEPAY1; break; case b: pay = BASEPAY2; break; case c: pay = BASEPAY3; break;

40、 case d: pay = BASEPAY4; break;default : printf(Please enter a, b, c, d, or q.n); menu();continue; f; taxes: $%.2f; net: $%.2fn, gross, taxes, net); menu(); printf(Done.n);return 0;void menu(void)printf( * *n);printf(Enter the letter corresponding to the desired pay rate or action:n);b) $%hrn, BASEP

41、AY1,d) $%hrn, BASEPAY3,BASEPAY2);BASEPAY4);printf(a) $%hrprintf(c) $%hrprintf(q) quitn);printf( *n);int getfirst(void) int ch;ch = getchar(); while (isspace(ch) ch = getchar(); while (getchar() != n)continue; return ch;Chapter 9PE9-1Programming Exercises/* Programming Exercise 9-1 */#include double

42、min(double, double); int main(void)double x, y; printf(Enter two numbers (q to quit): ); while (scanf(%lf %lf, &x, &y) = 2) printf(The smaller number is %f.n, min(x,y); printf(Next two values (q to quit): );printf(Bye!n);return 0;double min(double a, double b)return a b ? a : b;/* alternative implem

43、entation double min(double a, double b) if (a b) return a; else return b;*/PE 9-3/* Programming Exercise 9-3 */#include void chLineRow(char ch, int c, int r); int main(void) char ch; int col, row; printf(Enter a character (# to quit): ); while ( (ch = getchar() != #) if (ch = n)continue;printf(Enter

44、 number of columns and number of rows: ); if (scanf(%d %d, &col, &row) != 2) break; chLineRow(ch, col, row);printf(nEnter next character (# to quit): );printf(Bye!n);return 0;n, x, y); printf(Next two values (q to quit): );printf(Bye!n);return 0;void larger_of(double *p1, double *p2) if (*p1 *p2)*p2

45、 = *p1; else*p1 = *p2;Enter q); printf( to quit.n); while (scanf(%lf%d, &x, &n) = 2) xpow = power(x,n); /* function call */printf(%.3g to the power %d is %.5gn, x, n, xpow); printf(Enter next pair of numbers or q to quit.n); printf(Hope you enjoyed this power trip - bye!n); return 0; double power(do

46、uble a, int b) /* function definition */ double pow = 1; int i;if (b = 0) if (a= 0)printf(0 to the 0 undefined; using 1 as the valuen); pow = ; else if (a = 0) pow = ; else if (b 0) for(i = 1; i = b; i+) pow *= a; else /* b 0 */ pow = / power(a, - b);return pow; /* return the value of pow */ PE 9- 1

47、0/* Programming Exercise 9-10 */ #include void to_base_n(int x, int base); int main(void) int number; int b; int count; printf(Enter an integer (q to quit):n); while (scanf(%d, &number) = 1) printf(Enter number base (2-10): ); while (count = scanf(%d, &b)= 1& (b 10) printf(base should be in the rang

48、e 2-10: ); if (count != 1) break;printf(Base %d equivalent: , b); to_base_n(number, b); putchar(n);printf(Enter an integer (q to quit):n); printf(Done.n); return0; void to_base_n(int x, int base) /* recursive function */ int r; r = x % base; if (x = base) to_base_n(x / base, base); putchar(0 + r); r

49、eturn;Chapter 10 Programming ExercisesPE10-1/* Programming Exercise 10-1 */ #include #define MONTHS 12 f inches.nn, total/YRS); printf(MONTHLY AVERAGES:nn); printf( Jan Feb Mar Apr May Jun Jul Aug Sep Oct ); printf( Nov Decn); for (month = 0; month MONTHS; month+) /* for each month, sum rainfall ove

50、r years */ for (year =0, subtot =0; year YRS; year+) subtot += *(*(rain + year) + month); printf(% , subtot/YRS); printf(n); return 0; PE10-3/* Programming Exercise 10-3 */ #include #define LEN 10 int max_arr(const int ar, int n); void show_arr(const int ar, int n);int main(void)int origLEN = 1,2,3,

51、4,12,6,7,8,9,10; int max; show_arr(orig, LEN); max = max_arr(orig, LEN); printf(%d = largest valuen, max);return 0; int max_arr(const int ar, int n) int i; int max = ar0;/* dont use 0 as initial max value - fails if all array values are neg */for (i = 1; i n; i+) if(max ari) max = ari;return max;void show_arr(const int ar, int n) int i; for (i = 0; i n;i+) printf(%d , ari); putchar(n);PE 10-5/* Programming Exercise 10-5 */ #include #define LEN 10 double max_diff(const double ar, int n); void show_ar