blob: 79dff57499db660c0417000f4d528ed6e5c525a5 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
|
// FILE: useful.cxx
// IMPLEMENTS: A toolkit of functions (See useful.h for documentation.)
#include <assert.h> // Provides assert
#include <ctype.h> // Provides toupper
#include <iostream.h> // Provides cout, cin, get
#include <stdlib.h> // Provides rand, RAND_MAX
#include "useful.h"
void display(double x)
// Library facilities used: iostream.h, stdlib.h
{
const char STAR = '*';
const char BLANK = ' ';
const char VERTICAL_BAR = '|';
const int LIMIT = 39;
int i;
if (x < -LIMIT)
x = -LIMIT;
else if (x > LIMIT)
x = LIMIT;
for (i = -LIMIT; i < 0; i++)
{
if (i >= x)
cout << STAR;
else
cout << BLANK;
}
cout << VERTICAL_BAR;
for (i = 1; i <= LIMIT; i++)
{
if (i <= x)
cout << STAR;
else
cout << BLANK;
}
cout << endl;
}
double random_fraction( )
// Library facilities used: stdlib.h
{
return rand( ) / double(RAND_MAX);
}
double random_real(double low, double high)
// Library facilities used: assert.h
{
assert(low <= high);
return low + random_fraction( ) * (high - low);
}
void eat_line( )
// Library facilities used: iostream.h
//
{
char next;
do
cin.get(next);
while (next != '\n');
}
bool inquire(const char query[ ])
// Library facilities used: ctype.h, iostream.h
{
char answer;
do
{
cout << query << " [Yes or No]" << endl;
cin >> answer;
answer = toupper(answer);
eat_line( );
}
while ((answer != 'Y') && (answer != 'N'));
return (answer == 'Y');
}
|