RaspberryBASIC.org Forum

[John]

Can you post the complete script?

[jalih]

Can you post the complete script?

I think AIR ment:

Code: [Select]

# Python 3 - 1mil3.py

s = ""
t = ""
a = [None] * 1000001

for x in range(1000001):
  s += chr(((x) % 26) + 65)
  a[x] = x
  if len(s) == 26:
    t += s
    s = ""

r = "".join(reversed(t))

print("r LEN: {}".format(len(r)))
print("Front: {}".format(r[:26]))
print("Back:  {}".format(r[-26:]))
print("UBVal: {}".format(a[1000000]))


[John]

That code returns the following.


pi@RPi4B:~/python-dev/examples $ /usr/bin/time python3 1mil3.py
r LEN: 999986
Front: ZYXWVUTSRQPONMLKJIHGFEDCBA
Back:  ZYXWVUTSRQPONMLKJIHGFEDCBA
UBVal: None
1.92user 0.05system 0:01.97elapsed 99%CPU (0avgtext+0avgdata 32552maxresident)k
0inputs+0outputs (0major+7191minor)pagefaults 0swaps
pi@RPi4B:~/python-dev/examples $

[AIR]

something is not right on your end.

On my RPI 3B+

time python3 1mil3.py
r LEN: 999986
Front: ZYXWVUTSRQPONMLKJIHGFEDCBA
Back:  ZYXWVUTSRQPONMLKJIHGFEDCBA
UBVal: 1000000

real    0m6.103s
user    0m6.042s
sys    0m0.060s

[John]

Seems I had some file cross corruption.

Works on Python 2 & 3 now.

[AIR]

Hi AIR,

Do you have time to slap together a C submission for the third round? Maybe some pointer magic would make it scream.

Code: C

1. #define _GNU_SOURCE
2.  
3. #include <stdio.h>
4. #include <stdlib.h>
5. #include <string.h>
6.  
7. #define join(write_to,  ...) {           \
8.     char *tmp_string_for_extend = (write_to); \
9.     asprintf(&(write_to), __VA_ARGS__);       \
10.     free(tmp_string_for_extend);              \
11. }
12.  
13. char *strrev(char *str)
14. {
15.     if (!str || ! *str)
16.         return str;
17.  
18.     int i = strlen(str) - 1, j = 0;
19.  
20.     char ch;
21.     while (i > j) {
22.         ch = str[i];
23.         str[i] = str[j];
24.         str[j] = ch;
25.         i--;
26.         j++;
27.     }
28.     return str;
29. }
30.  
31.  
32. int main() {
33.     int a[1000001] = {0};
34.     int i;
35.     char *s=NULL,*t=NULL;
36.  
37.     join(s,"");
38.     join(t,"");
39.  
40.     for (int x = 0; x < 1000001; x++) {
41.         a[x] = x;
42.  
43.         join(s,"%s%c",s,(x%26)+65);
44.  
45.         if (strlen(s) == 26) {
46.             join(t,"%s%s",t,s);
47.             join(s,"");
48.         }
49.     }
50.  
51.     free(s);
52.     strrev(t);
53.  
54.     printf("r LEN: %lu\n",strlen(t));
55.     printf("Front: %.*s\n", 26, t);
56.     printf("Back: %s\n", t + strlen(t) - 26);
57.     printf("UBVal: %d\n",a[1000000]);
58.  
59. }

AIR.

[John]

I'm working on the Swift round 3 submission and it is running really slow. I don't have the array part working yet but even compiled doesn't seem  to make  a big difference. Any suggestions or code would be appreciated.

Code: Text

1. // Swift 5.1.2 - 1mil3.swift
2.  
3. var s = ""
4. var t = ""
5. // var a = [Int]()
6.  
7. for x in 1...1000000 {
8.   s += String(UnicodeScalar(UInt8(((x - 1) % 26) + 65)))
9. //  a[x] = x
10.   if s.count == 26 {
11.     t = t + s
12.     s = ""
13.   }
14. }
15.  
16. let r = String(t.reversed())
17.  
18. print("r LEN: ", r.count)
19. print("Front: \(r.prefix(26))")
20. print("Back:  \(r.suffix(26))")
21. // print("UBVal: ", a[100000])
22.  

pi@RPi4B:~/swift-dev/examples $ /usr/bin/time ./main
r LEN:  999986
Front: ZYXWVUTSRQPONMLKJIHGFEDCBA
Back:  ZYXWVUTSRQPONMLKJIHGFEDCBA
338.87user 35.15system 6:14.07elapsed 99%CPU (0avgtext+0avgdata 10344maxresident)k
0inputs+0outputs (0major+4026645minor)pagefaults 0swaps
pi@RPi4B:~/swift-dev/examples $

[jalih]

I'm working on the Swift round 3 submission and if is running really slow. I don't have the array part working yet but even compiled doesn't seem  to make  a big difference. Any suggestions or code would be appreciated.

Test what is the time without reversing the string. It took 8th a very long time to finish the task and the culprit was the s:rev not trying to optimize in case of ASCII string (It's already fixed for the next release.). It took over 30 minutes to finish...

I don't know if it's cheating or not but just use:

Code: [Select]

t.reversed()
Instead of:

Code: [Select]

String(t.reversed())

It's a lot faster just enumerating the characters from back to front without building a new collection for a reversed string. Some call it cheating, I call it smart thing to do!

[John]

Great job on the C submission AIR!

I wasn't looking forward to having to do that one. My hero.

[John]

It looks like string reverse is the problem with Swift.

Code: Text

1. // Swift 5.1.2 - 1mil3.swift
2.  
3. var s = ""
4. var t = ""
5. var r = ""
6.  
7. // var a = [Int]()
8.  
9. for x in 1...1000000 {
10.   s += String(UnicodeScalar(UInt8(((x - 1) % 26) + 65)))
11. //  a[x] = x
12.   if s.count == 26 {
13. //  t += s
14.     r += s  
15.     s = ""
16.   }
17. }
18.  
19. // let r = String(t.reversed())
20.  
21. print("r LEN: ", r.count)
22. print("Front: \(r.prefix(26))")
23. print("Back:  \(r.suffix(26))")
24. // print("UBVal: ", a[100000])
25.  

pi@RPi4B:~/swift-dev/examples $ /usr/bin/time ./main
r LEN:  999986
Front: ABCDEFGHIJKLMNOPQRSTUVWXYZ
Back:  ABCDEFGHIJKLMNOPQRSTUVWXYZ
35.55user 0.01system 0:35.59elapsed 99%CPU (0avgtext+0avgdata 8508maxresident)k
800inputs+0outputs (3major+918minor)pagefaults 0swaps
pi@RPi4B:~/swift-dev/examples $



@Jalih: I tried your t.reversed() idea but Swift complained.


pi@RPi4B:~/swift-dev/examples $ swiftc 1mil3.swift
1mil3.swift:21:7: error: cannot assign value of type 'ReversedCollection<String>' to type 'String'
r = t.reversed()
    ~~^~~~~~~~~~
pi@RPi4B:~/swift-dev/examples $
[/tt\

[John]

AIR,

Here is the results of your C submission.


pi@RPi4B:~/c-dev/examples $ gcc -O3 1mil3.c -o 1mil3
pi@RPi4B:~/c-dev/examples $ ls -l 1mil3
-rwxr-xr-x 1 pi pi 8140 Dec  1 11:23 1mil3
pi@RPi4B:~/c-dev/examples $ /usr/bin/time ./1mil3
r LEN: 999986
Front: ZYXWVUTSRQPONMLKJIHGFEDCBA
Back: ZYXWVUTSRQPONMLKJIHGFEDCBA
UBVal: 1000000
45.56user 63.56system 1:49.17elapsed 99%CPU (0avgtext+0avgdata 23956maxresident)k
0inputs+0outputs (0major+7535448minor)pagefaults 0swaps
pi@RPi4B:~/c-dev/examples $

[AIR]

AIR,

Here is the results of your C submission.

Yep, it's not the most optimized way of implementing this, but you didn't want predefined buffers.  This implementation creates a new buffer each time 'join' is called and concats the data, which is expensive.

BTW, your swift code compiles and runs fine on my Mac Mini.  There is a difference when compiled in debug mode (the default) and release mode.

[riveraa@mini ~/Projects/Swift/blah] $ time .build/x86_64-apple-macosx10.10/release/blah
r LEN:  999986
Front: ZYXWVUTSRQPONMLKJIHGFEDCBA
Back:  ZYXWVUTSRQPONMLKJIHGFEDCBA

real    0m1.979s
user    0m1.846s
sys    0m0.130s

[riveraa@mini ~/Projects/Swift/blah] $ time .build/x86_64-apple-macosx10.10/debug/blah
r LEN:  999986
Front: ZYXWVUTSRQPONMLKJIHGFEDCBA
Back:  ZYXWVUTSRQPONMLKJIHGFEDCBA

real    0m2.678s
user    0m2.541s
sys    0m0.132s

For comparison, the C code executed on my Mac Mini:

r LEN: 999986
Front: ZYXWVUTSRQPONMLKJIHGFEDCBA
Back: ZYXWVUTSRQPONMLKJIHGFEDCBA
UBVal: 1000000

real    0m2.554s
user    0m2.405s
sys    0m0.145s

[John]

ScriptBasic is acting cooky about its 50 second run.

I wonder what FreeBasic is doing under the covers with its conversion to C? Damn fast.

[AIR]

Code: Go

1. package main
2.  
3. import (
4.     "fmt"
5. )
6.  
7. // Reverse returns its argument string reversed rune-wise left to right.
8. // From: https://github.com/golang/example/blob/master/stringutil/reverse.go
9. func Reverse(s string) string {
10.     r := []rune(s)
11.     for i, j := 0, len(r)-1; i < len(r)/2; i, j = i+1, j-1 {
12.         r[i], r[j] = r[j], r[i]
13.     }
14.     return string(r)
15. }
16.  
17. func main() {
18.     var s = ""
19.     var t = ""
20.     var a [1000001]int
21.  
22.     for x := 0; x < 1000001; x++ {
23.         a[x] = x
24.  
25.         s += string((x % 26) + 65)
26.  
27.         if len(s) == 26 {
28.             t += s
29.             s = ""
30.         }
31.     }
32.  
33.     t = Reverse(t)
34.  
35.     fmt.Println("r LEN: ", len(t))
36.     fmt.Println("Front: ", t[0:26])
37.     fmt.Println("Back:  ", t[len(t)-26:])
38.     fmt.Println("UBVal: ", a[1000000])
39.  
40. }

[John]

Nice GOing!


pi@RPi4B:~/go-dev/examples $ go build 1mil3.go
pi@RPi4B:~/go-dev/examples $ /usr/bin/time ./1mil3
r LEN:  999986
Front:  ZYXWVUTSRQPONMLKJIHGFEDCBA
Back:   ZYXWVUTSRQPONMLKJIHGFEDCBA
UBVal:  1000000
22.88user 4.71system 0:21.92elapsed 125%CPU (0avgtext+0avgdata 27036maxresident)k
0inputs+0outputs (0major+6656minor)pagefaults 0swaps
pi@RPi4B:~/go-dev/examples $