C Primer Plus第6版编程练习答案

}

PE 5--‐5

/* Programming Exercise 5-5 */ #include <>

int main(void) /* finds sum of first n integers */ {

int count, sum; int n;

printf(\

scanf(\sum = 0; while

(count++ < n) sum = sum + count; printf(\0; }

PE 5--‐7

/* Programming Exercise 5-7 */ #include <> void

showCube(double x);

int main(void) /* finds cube of entered number */ { double val;

printf(\scanf(\return 0; }

void showCube(double x) {

printf(\}

Chapter 6 Programming Exercises

PE 6--‐1

/* */

/* this implementation assumes the character codes */ /* are sequential, as they are in ASCII. */ #include <> #define SIZE 26 int main( void ) { char

lcase[SIZE]; int i; for (i = 0; i < SIZE; i++) lcase[i] = 'a' + i; for (i = 0; i < SIZE; i++) printf(\printf(\return 0; }

PE 6--‐3

/* */

/* this implementation assumes the character codes */ /* are sequential, as they are in ASCII. */

#include <> int main( void ) { char let =

'F'; char start; char end;

for (end = let; end >= 'A'; end--) {

for (start = let; start >= end; start--) printf(\ } return 0; }

PE 6--‐6

/* */ #include <> int main( void )

{ int lower, upper,

index; int square, cube;

printf(\scanf(\ending integer: \&upper);

printf(\\index++)

{ square = index * index; cube = index * square;

printf(\ } return 0; }

PE 6--‐8

/* */ #include <> int main( void ) { double n, m; double res;

printf(\

while (scanf(\ {

res = (n - m) / (n * m);

printf(\printf(\ }

return 0; }

PE 6--‐11

/* */

#include <>

#define SIZE 8 int main( void ) { int

vals[SIZE]; int i;

printf(\for (i = 0; i < SIZE; i++) scanf(\&vals[i]);

printf(\for (i = SIZE - 1; i >= 0; i--) printf(\printf(\}

PE 6--‐13

/* */

/* This version starts with the 0 power */ #include <>

#define SIZE 8 int main( void ) {

int twopows[SIZE]; int i;

int value = 1; /* 2 to the 0 */

for (i = 0; i < SIZE; i++) { twopows[i] = value; value *= 2; } i = 0; do {

printf(\i++; } while (i < SIZE);

printf(\return 0; }

PE 6--‐14

/* */

/* Programming Exercise 6-14 */ #include <>

#define SIZE 8 int main(void)

{ double arr[SIZE]; double arr_cumul[SIZE]; int i;

printf(\SIZE);

for (i = 0; i < SIZE; i++) {

printf(\scanf(\scanf(\ }

arr_cumul[0] = arr[0]; /* set first element */ for (i = 1; i < SIZE; i++)

arr_cumul[i] = arr_cumul[i-1] + arr[i]; for (i = 0; i < SIZE; i++) printf(\

printf(\SIZE; i++) printf(\

arr_cumul[i]); printf(\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_COMP * deidre;

++years; }

printf(\printf(\$%.2f\\n\}

Chapter 7 Programming Exercises

PE 7--‐1

/* Programming Exercise 7-1 */ #include <> int main(void) { char ch; int sp_ct = 0; int nl_ct = 0;

int other = 0; while ((ch =

getchar()) != '#') {

if (ch == ' ') sp_ct++; else if (ch

== '\\n') nl_ct++; else other++; }

printf(\ return 0; }

PE 7--‐3

/* Programming Exercise 7-3 */