|
1
|
#include <stdio.h>
|
|
2
|
#include <time.h>
|
|
3
|
#include <termios.h>
|
|
4
|
#include <errno.h>
|
|
5
|
#include <fcntl.h>
|
|
6
|
#include <QList>
|
|
7
|
|
|
8
|
|
|
9
|
int size=0x1000000;
|
|
10
|
|
|
11
|
int distance(int front, int back)
|
|
12
|
{
|
|
13
|
if( front > back )
|
|
14
|
{
|
|
15
|
return(size-(front-back));
|
|
16
|
}
|
|
17
|
return( back-front );
|
|
18
|
}
|
|
19
|
|
|
20
|
void right(int& front, int&back, int mid)
|
|
21
|
{
|
|
22
|
front=mid;
|
|
23
|
}
|
|
24
|
|
|
25
|
void left(int& front, int&back, int mid)
|
|
26
|
{
|
|
27
|
back=mid;
|
|
28
|
}
|
|
29
|
|
|
30
|
int steps=0;
|
|
31
|
int search(int front, int back, int value)
|
|
32
|
{
|
|
33
|
steps=0;
|
|
34
|
int mid;
|
|
35
|
|
|
36
|
while( distance(front, back) > 1 )
|
|
37
|
{
|
|
38
|
mid=(front+(distance(front,back)/2)) % size;
|
|
39
|
if(mid<value)
|
|
40
|
{
|
|
41
|
right(front, back, mid);
|
|
42
|
}
|
|
43
|
else
|
|
44
|
{
|
|
45
|
left(front, back, mid);
|
|
46
|
}
|
|
47
|
steps++;
|
|
48
|
}
|
|
49
|
|
|
50
|
printf(" Front: 0x%X; Back: 0x%X; distance: %d; value: 0x%X\n", front, back, distance(front, back), value );
|
|
51
|
if( front == value )
|
|
52
|
{
|
|
53
|
printf(" F\n");
|
|
54
|
return( front );
|
|
55
|
}
|
|
56
|
|
|
57
|
printf(" B\n");
|
|
58
|
return( back );
|
|
59
|
}
|
|
60
|
|
|
61
|
|
|
62
|
int main() {
|
|
63
|
|
|
64
|
|
|
65
|
int front=0;
|
|
66
|
int back=size-1;
|
|
67
|
int found=search(front, back, 0x12000);
|
|
68
|
printf("1. Result: 0x%X; steps: %d\n", found, steps);
|
|
69
|
|
|
70
|
front++;
|
|
71
|
found=search(front, back, 0x12000);
|
|
72
|
printf("2. Result: 0x%X; steps: %d\n", found, steps);
|
|
73
|
|
|
74
|
front++;
|
|
75
|
found=search(front, back, 0x12001);
|
|
76
|
printf("3. Result: 0x%X; steps: %d\n", found, steps);
|
|
77
|
|
|
78
|
front=size-0x100;
|
|
79
|
back=0x100;
|
|
80
|
found=search(front, back, 0x12001);
|
|
81
|
printf("3. Result: 0x%X; steps: %d\n", found, steps);
|
|
82
|
|
|
83
|
return 0;
|
|
84
|
}
|