WeixiangYan/CodeTransOcean huggingface dataset:
Task: Mad Libs








VB: Function mad_libs(s)
    Do
        If InStr(1,s,"<") <> 0 Then
            start_position = InStr(1,s,"<") + 1
            end_position = InStr(1,s,">")
            parse_string = Mid(s,start_position,end_position-start_position)
            WScript.StdOut.Write parse_string & "? "
            input_string = WScript.StdIn.ReadLine
            s = Replace(s,"<" & parse_string & ">",input_string)
        Else
            Exit Do
        End If
    Loop
    mad_libs = s
End Function

WScript.StdOut.Write mad_libs("<name> went for a walk in the park. <he or she> found a <noun>. <name> decided to take it home.")
WScript.StdOut.WriteLine
Task: CSV to HTML translation








VB: Public Sub CSV_TO_HTML()
    input_ = "Character,Speech\n" & _
        "The multitude,The messiah! Show us the messiah!\n" & _
        "Brians mother,<angry>Now you listen here! He
            "he
        "The multitude,Who are you?\n" & _
        "Brians mother,I
        "The multitude,Behold his mother! Behold his mother!"
     
    Debug.Print "<table>" & vbCrLf & "<tr><td>"
    For i = 1 To Len(input_)
        Select Case Mid(input_, i, 1)
            Case "\"
                If Mid(input_, i + 1, 1) = "n" Then
                    Debug.Print "</td></tr>" & vbCrLf & "<tr><td>";
                    i = i + 1
                Else
                    Debug.Print Mid(input_, i, 1);
                End If
            Case ",": Debug.Print "</td><td>";
            Case "<": Debug.Print "&lt;";
            Case ">": Debug.Print "&gt;";
            Case "&": Debug.Print "&amp;";
            Case Else: Debug.Print Mid(input_, i, 1);
        End Select
    Next i
    Debug.Print "</td></tr>" & vbCrLf & "</table>"
End Sub
Task: Pythagorean triples








VB: Dim total As Variant, prim As Variant, maxPeri As Variant
Private Sub newTri(s0 As Variant, s1 As Variant, s2 As Variant)
    Dim p As Variant
    p = CDec(s0) + CDec(s1) + CDec(s2)
    If p <= maxPeri Then
        prim = prim + 1
        total = total + maxPeri \ p
        newTri s0 + 2 * (-s1 + s2), 2 * (s0 + s2) - s1, 2 * (s0 - s1 + s2) + s2
        newTri s0 + 2 * (s1 + s2), 2 * (s0 + s2) + s1, 2 * (s0 + s1 + s2) + s2
        newTri -s0 + 2 * (s1 + s2), 2 * (-s0 + s2) + s1, 2 * (-s0 + s1 + s2) + s2
      End If
End Sub
Public Sub Program_PythagoreanTriples()
    maxPeri = CDec(100)
    Do While maxPeri <= 10000000#
        prim = CDec(0)
        total = CDec(0)
        newTri 3, 4, 5
        Debug.Print "Up to "; maxPeri; ": "; total; " triples, "; prim; " primitives."
        maxPeri = maxPeri * 10
    Loop
End Sub
Task: Soundex








VB: 
    tt=array( _
      "Ashcraft","Ashcroft","Gauss","Ghosh","Hilbert","Heilbronn","Lee","Lloyd", _
      "Moses","Pfister","Robert","Rupert","Rubin","Tymczak","Soundex","Example")
    tv=array( _
      "A261","A261","G200","G200","H416","H416","L000","L300", _
      "M220","P236","R163","R163","R150","T522","S532","E251")
    For i=lbound(tt) To ubound(tt)
        ts=soundex(tt(i))
        If ts<>tv(i) Then ok=" KO "& tv(i) Else ok=""
        Wscript.echo right(" "& i ,2) & " " & left( tt(i) &space(12),12) & " " & ts & ok
    Next 
    
Function getCode(c)
    Select Case c
        Case "B", "F", "P", "V"
            getCode = "1"
        Case "C", "G", "J", "K", "Q", "S", "X", "Z"
            getCode = "2"
        Case "D", "T"
            getCode = "3"
        Case "L"
            getCode = "4"
        Case "M", "N"
            getCode = "5"
        Case "R"
            getCode = "6"
        Case "W","H"
            getCode = "-"
    End Select
End Function 
 
Function soundex(s)
    Dim code, previous, i
    code = UCase(Mid(s, 1, 1))
    previous = getCode(UCase(Mid(s, 1, 1)))
    For i = 2 To Len(s)
        current = getCode(UCase(Mid(s, i, 1)))
        If current <> "" And current <> "-" And current <> previous Then code = code & current
        If current <> "-" Then previous = current
    Next 
    soundex = Mid(code & "000", 1, 4)
End Function
Task: Flow-control structures








VB:   Sub bar2()
      Dim x = 0
      GoTo label
      x = 5
label:
      Console.WriteLine(x)
  End Sub
Task: Return multiple values








VB: Type Contact
    Name As String
    firstname As String
    Age As Byte
End Type

Function SetContact(N As String, Fn As String, A As Byte) As Contact
    SetContact.Name = N
    SetContact.firstname = Fn
    SetContact.Age = A
End Function


Sub Test_SetContact()
Dim Cont As Contact

    Cont = SetContact("SMITH", "John", 23)
    Debug.Print Cont.Name & " " & Cont.firstname & ", " & Cont.Age & " years old."
End Sub
Task: Substring_Top and tail








VB: string = "Small Basic"
TextWindow.WriteLine(Text.GetSubTextToEnd(string, 2)) 
TextWindow.WriteLine(Text.GetSubText(string, 1, Text.GetLength(string) - 1)) 
TextWindow.WriteLine(Text.GetSubText(string, 2, Text.GetLength(string) - 2))
Task: Plot coordinate pairs








VB: Private Sub plot_coordinate_pairs(x As Variant, y As Variant)
    Dim chrt As Chart
    Set chrt = ActiveSheet.Shapes.AddChart.Chart
    With chrt
        .ChartType = xlLine
        .HasLegend = False
        .HasTitle = True
        .ChartTitle.Text = "Time"
        .SeriesCollection.NewSeries
        .SeriesCollection.Item(1).XValues = x
        .SeriesCollection.Item(1).Values = y
        .Axes(xlValue, xlPrimary).HasTitle = True
        .Axes(xlValue, xlPrimary).AxisTitle.Characters.Text = "microseconds"
    End With
End Sub
Public Sub main()
    x = [{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}]
    y = [{2.7, 2.8, 31.4, 38.1, 58.0, 76.2, 100.5, 130.0, 149.3, 180.0}]
    plot_coordinate_pairs x, y
End Sub
Task: Text processing_1








VB: Set objFSO = CreateObject("Scripting.FileSystemObject")
Set objFile = objFSO.OpenTextFile(objFSO.GetParentFolderName(WScript.ScriptFullName) &_
			"\data.txt",1)

bad_readings_total = 0
good_readings_total = 0
data_gap = 0
start_date = ""
end_date = ""
tmp_datax_gap = 0
tmp_start_date = ""

Do Until objFile.AtEndOfStream
	bad_readings = 0
	good_readings = 0
	line_total = 0
	line = objFile.ReadLine
	token = Split(line,vbTab)
	n = 1
	Do While n <= UBound(token)
		If n + 1 <= UBound(token) Then
			If CInt(token(n+1)) < 1 Then
				bad_readings = bad_readings + 1
				bad_readings_total = bad_readings_total + 1
				
				If tmp_start_date = "" Then
					tmp_start_date = token(0)
				End If
				tmp_data_gap = tmp_data_gap + 1
			Else
				good_readings = good_readings + 1
				line_total = line_total + CInt(token(n))
				good_readings_total = good_readings_total + 1
				
				If (tmp_start_date <> "") And (tmp_data_gap > data_gap) Then
					start_date = tmp_start_date
					end_date = token(0)
					data_gap = tmp_data_gap
					tmp_start_date = ""
					tmp_data_gap = 0
				Else
					tmp_start_date = ""
					tmp_data_gap = 0
				End If
			End If	
		End If
		n = n + 2
	Loop
	line_avg = line_total/good_readings
	WScript.StdOut.Write "Date: " & token(0) & vbTab &_
		"Bad Reads: " & bad_readings & vbTab &_
		"Good Reads: " & good_readings & vbTab &_
		"Line Total: " & FormatNumber(line_total,3) & vbTab &_
		"Line Avg: " & FormatNumber(line_avg,3)
	WScript.StdOut.WriteLine
Loop
WScript.StdOut.WriteLine
WScript.StdOut.Write "Maximum run of " & data_gap &_ 
	" consecutive bad readings from " & start_date & " to " &_
	end_date & "."
WScript.StdOut.WriteLine
objFile.Close
Set objFSO = Nothing
Task: Colour pinstripe_Display








VB: Public Class Main
    Inherits System.Windows.Forms.Form
    Public Sub New()
        Me.FormBorderStyle = FormBorderStyle.None
        Me.WindowState = FormWindowState.Maximized
    End Sub
    Private Sub Main_Load(sender As Object, e As EventArgs) Handles Me.Load
        Dim Index As Integer
        Dim Colors() As Color = {Color.Black, Color.Red, Color.Green, Color.Magenta, Color.Cyan, Color.Yellow, Color.White}
        Dim Height = (Me.ClientSize.Height / 4) + 1
        For y = 1 To 4
            Dim Top = Me.ClientSize.Height / 4 * (y - 1)
            For x = 0 To Me.ClientSize.Width Step y
                If Index = 6 Then Index = 0 Else Index += 1
                Me.Controls.Add(New Panel With {.Top = Top, .Height = Height, .Left = x, .Width = y, .BackColor = Colors(Index)})
            Next
        Next
    End Sub
End Class
Task: Pythagorean triples






PHP: <?php
 
function gcd($a, $b)
{
    if ($a == 0)
       return $b;
    if ($b == 0)
       return $a;
    if($a == $b)
        return $a;
    if($a > $b)
        return gcd($a-$b, $b);
    return gcd($a, $b-$a);
}

$pytha = 0;
$prim = 0;
$max_p = 100;

for ($a = 1; $a <= $max_p / 3; $a++) {
    $aa = $a**2;
    for ($b = $a + 1; $b < $max_p/2; $b++) {
        $bb = $b**2;
        for ($c = $b + 1; $c < $max_p/2; $c++) {
            $cc = $c**2;
            if ($aa + $bb < $cc) break;
            if ($a + $b + $c > $max_p) break;

            if ($aa + $bb == $cc) {
                $pytha++;
                if (gcd($a, $b) == 1) $prim++;
            }
        }
    }
}

echo 'Up to ' . $max_p . ', there are ' . $pytha . ' triples, of which ' . $prim . ' are primitive.';
Task: Gray code






PHP: <?php




function gray_encode($binary){
	return $binary ^ ($binary >> 1);
}


function gray_decode($gray){
	$binary = $gray;
	while($gray >>= 1) $binary ^= $gray;
	return $binary;
}

for($i=0;$i<32;$i++){
	$gray_encoded = gray_encode($i);
	printf("%2d : %05b => %05b => %05b : %2d \n",$i, $i, $gray_encoded, $gray_encoded, gray_decode($gray_encoded));
}
Task: Soundex






PHP: <?php
echo soundex("Soundex"), "\n"; // S532
echo soundex("Example"), "\n"; // E251
echo soundex("Sownteks"), "\n"; // S532
echo soundex("Ekzampul"), "\n"; // E251
?>
Task: Return multiple values






PHP: function addsub($x, $y) {
  return array($x + $y, $x - $y);
}
Task: Substring_Top and tail






PHP: <?php
echo substr("knight", 1), "\n";       // strip first character
echo substr("socks", 0, -1), "\n";    // strip last character
echo substr("brooms", 1, -1), "\n";   // strip both first and last characters
?>
Task: LZW compression






PHP: class LZW
{
    function compress($unc) {
        $i;$c;$wc;
        $w = "";
        $dictionary = array();
        $result = array();
        $dictSize = 256;
        for ($i = 0; $i < 256; $i += 1) {
            $dictionary[chr($i)] = $i;
        }
        for ($i = 0; $i < strlen($unc); $i++) {
            $c = $unc[$i];
            $wc = $w.$c;
            if (array_key_exists($w.$c, $dictionary)) {
                $w = $w.$c;
            } else {
                array_push($result,$dictionary[$w]);
                $dictionary[$wc] = $dictSize++;
                $w = (string)$c;
            }
        }
        if ($w !== "") {
            array_push($result,$dictionary[$w]);
        }
        return implode(",",$result);
    }

    function decompress($com) {
        $com = explode(",",$com);
        $i;$w;$k;$result;
        $dictionary = array();
        $entry = "";
        $dictSize = 256;
        for ($i = 0; $i < 256; $i++) {
            $dictionary[$i] = chr($i);
        }
        $w = chr($com[0]);
        $result = $w;
        for ($i = 1; $i < count($com);$i++) {
            $k = $com[$i];
            if (isset($dictionary[$k])) {
                $entry = $dictionary[$k];
            } else {
                if ($k === $dictSize) {
                    $entry = $w.$w[0];
                } else {
                    return null;
                }
            }
            $result .= $entry;
            $dictionary[$dictSize++] = $w . $entry[0];
            $w = $entry;
        }
        return $result;
    }
}

$str = 'TOBEORNOTTOBEORTOBEORNOT';
$lzw = new LZW();
$com = $lzw->compress($str);
$dec = $lzw->decompress($com);
echo $com . "<br>" . $dec;
Task: Longest string challenge






PHP: <?php

echo 'Enter strings (empty string to finish) :', PHP_EOL;

$output = $previous = readline();
while ($current = readline()) {
    $p = $previous;
    $c = $current;

    while ($p and $c) {
        $p = substr($p, 1);
        $c = substr($c, 1);
    }

    if (!$p and !$c) {
        $output .= PHP_EOL . $current;
    }

    if ($c) {
        $output = $previous = $current;
    }
}

echo 'Longest string(s) = ', PHP_EOL, $output, PHP_EOL;
Task: Pascal matrix generation

C: #include <stdio.h>
#include <stdlib.h>

void pascal_low(int **mat, int n) {
    int i, j;

    for (i = 0; i < n; ++i)
        for (j = 0; j < n; ++j)
            if (i < j)
                mat[i][j] = 0;
            else if (i == j || j == 0)
                mat[i][j] = 1;
            else
                mat[i][j] = mat[i - 1][j - 1] + mat[i - 1][j];
}

void pascal_upp(int **mat, int n) {
    int i, j;

    for (i = 0; i < n; ++i)
        for (j = 0; j < n; ++j)
            if (i > j)
                mat[i][j] = 0;
            else if (i == j || i == 0)
                mat[i][j] = 1;
            else
                mat[i][j] = mat[i - 1][j - 1] + mat[i][j - 1];
}

void pascal_sym(int **mat, int n) {
    int i, j;

    for (i = 0; i < n; ++i)
        for (j = 0; j < n; ++j)
            if (i == 0 || j == 0)
                mat[i][j] = 1;
            else
                mat[i][j] = mat[i - 1][j] + mat[i][j - 1];
}

int main(int argc, char * argv[]) {
    int **mat;
    int i, j, n;

    
    n = 5;

    
    mat = calloc(n, sizeof(int *));
    for (i = 0; i < n; ++i)
        mat[i] = calloc(n, sizeof(int));

    
    printf("=== Pascal upper matrix ===\n");
    pascal_upp(mat, n);
    for (i = 0; i < n; i++)
        for (j = 0; j < n; j++)
            printf("%4d%c", mat[i][j], j < n - 1 ? ' ' : '\n');

    printf("=== Pascal lower matrix ===\n");
    pascal_low(mat, n);
    for (i = 0; i < n; i++)
        for (j = 0; j < n; j++)
            printf("%4d%c", mat[i][j], j < n - 1 ? ' ' : '\n');

    printf("=== Pascal symmetric matrix ===\n");
    pascal_sym(mat, n);
    for (i = 0; i < n; i++)
        for (j = 0; j < n; j++)
            printf("%4d%c", mat[i][j], j < n - 1 ? ' ' : '\n');

    return 0;
}
Task: FASTA format

C: #include <stdio.h>
#include <stdlib.h>
#include <string.h>

void main()
{
	FILE * fp;
	char * line = NULL;
	size_t len = 0;
	ssize_t read;

	fp = fopen("fasta.txt", "r");
	if (fp == NULL)
		exit(EXIT_FAILURE);

	int state = 0;
	while ((read = getline(&line, &len, fp)) != -1) {
		
		if (line[read - 1] == '\n')
			line[read - 1] = 0;
		
		if (line[0] == '>') {
			if (state == 1)
				printf("\n");
			printf("%s: ", line+1);
			state = 1;
		} else {
			
			printf("%s", line);
		}
	}
	printf("\n");

	fclose(fp);
	if (line)
		free(line);
	exit(EXIT_SUCCESS);
}
Task: Validate International Securities Identification Number

C: #include <stdio.h>

int check_isin(char *a) {
    int i, j, k, v, s[24];
    
    j = 0;
    for(i = 0; i < 12; i++) {
        k = a[i];
        if(k >= '0' && k <= '9') {
            if(i < 2) return 0;
            s[j++] = k - '0';
        } else if(k >= 'A' && k <= 'Z') {
            if(i == 11) return 0;
            k -= 'A' - 10;
            s[j++] = k / 10;
            s[j++] = k % 10;
        } else {
            return 0;
        }
    }
    
    if(a[i]) return 0;
    
    v = 0;
    for(i = j - 2; i >= 0; i -= 2) {
        k = 2 * s[i];
        v += k > 9 ? k - 9 : k;
    }
    
    for(i = j - 1; i >= 0; i -= 2) {
        v += s[i];
    }
    
    return v % 10 == 0;
}

int main() {
    char *test[7] = {"US0378331005", "US0373831005", "U50378331005",
                     "US03378331005", "AU0000XVGZA3", "AU0000VXGZA3",
                     "FR0000988040"};
    int i;
    for(i = 0; i < 7; i++) printf("%c%c", check_isin(test[i]) ? 'T' : 'F', i == 6 ? '\n' : ' ');
    return 0;
}
Task: Sum of first n cubes

C: #include <stdio.h>

int main() {
    for (int i = 0, sum = 0; i < 50; ++i) {
        sum += i * i * i;
        printf("%7d%c", sum, (i + 1) % 5 == 0 ? '\n' : ' ');
    }
    return 0;
}
Task: Verify distribution uniformity_Chi-squared test

C: #include <stdlib.h>
#include <stdio.h>
#include <math.h>
#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif

typedef double (* Ifctn)( double t);

double Simpson3_8( Ifctn f, double a, double b, int N)
{
    int j;
    double l1;
    double h = (b-a)/N;
    double h1 = h/3.0;
    double sum = f(a) + f(b);

    for (j=3*N-1; j>0; j--) {
        l1 = (j%3)? 3.0 : 2.0;
        sum += l1*f(a+h1*j) ;
    }
    return h*sum/8.0;
}

#define A 12
double Gamma_Spouge( double z )
{
    int k;
    static double cspace[A];
    static double *coefs = NULL;
    double accum;
    double a = A;

    if (!coefs) {
        double k1_factrl = 1.0;
        coefs = cspace;
        coefs[0] = sqrt(2.0*M_PI);
        for(k=1; k<A; k++) {
            coefs[k] = exp(a-k) * pow(a-k,k-0.5) / k1_factrl;
            k1_factrl *= -k;
        }
    }

    accum = coefs[0];
    for (k=1; k<A; k++) {
        accum += coefs[k]/(z+k);
    }
    accum *= exp(-(z+a)) * pow(z+a, z+0.5);
    return accum/z;
}

double aa1;
double f0( double t)
{
    return  pow(t, aa1)*exp(-t); 
}

double GammaIncomplete_Q( double a, double x)
{
    double y, h = 1.5e-2;  

    
    y = aa1 = a-1;
    while((f0(y) * (x-y) > 2.0e-8) && (y < x))   y += .4;
    if (y>x) y=x;

    return 1.0 - Simpson3_8( &f0, 0, y, (int)(y/h))/Gamma_Spouge(a);
}
Task: CSV to HTML translation

C: #include <stdio.h>

const char *input = 
	"Character,Speech\n"
	"The multitude,The messiah! Show us the messiah!\n"
	"Brians mother,<angry>Now you listen here! He's not the messiah; "
		"he's a very naughty boy! Now go away!</angry>\n"
	"The multitude,Who are you?\n"
	"Brians mother,I'm his mother; that's who!\n"
	"The multitude,Behold his mother! Behold his mother!";

int main()
{
	const char *s;
	printf("<table>\n<tr><td>");
	for (s = input; *s; s++) {
		switch(*s) {
		case '\n': printf("</td></tr>\n<tr><td>"); break;
		case ',':  printf("</td><td>"); break;
		case '<':  printf("&lt;"); break;
		case '>':  printf("&gt;"); break;
		case '&':  printf("&amp;"); break;
		default:   putchar(*s);
		}
	}
	puts("</td></tr>\n</table>");

	return 0;
}
Task: Count how many vowels and consonants occur in a string

C: 

#include <stdio.h>

char vowels[] = {'a','e','i','o','u','\n'};

int len(char * str) {
	int i = 0;
	while (str[i] != '\n') i++;
	return i;
}

int  isvowel(char c){
	int b = 0;
	int v = len(vowels);
	for(int i = 0; i < v;i++) {
		if(c == vowels[i]) {
			b = 1;
			break; 
		}
	}
	return b;
}

int isletter(char c){
	return ((c >= 'a') && (c <= 'z') || (c >= 'A') && (c <= 'Z'));
}

int isconsonant(char c){
	return isletter(c) && !isvowel(c);
}

int cVowels(char * str) {
	int i = 0;
	int count = 0;
	while (str[i] != '\n') {
		if (isvowel(str[i])) {
			count++;;
		}
		i++;
	}
	return count;
}

int cConsonants(char * str ) {
	int i = 0;
	int count = 0;
	while (str[i] != '\n') {
		if (isconsonant(str[i])) {
			count++;
		}
		i++;
	}
	return count;
}

int main() {

	char buff[] = "This is 1 string\n";
	printf("%4d, %4d, %4d, %s\n", cVowels(buff), cConsonants(buff), len(buff), buff);

	char buff2[] = "This is a second string\n";
	printf("%4d, %4d, %4d, %s\n", cVowels(buff2), cConsonants(buff2), len(buff2),  buff2);


	printf("a: %d\n", isvowel('a'));
	printf("b: %d\n", isvowel('b'));
	printf("Z: %d\n", isconsonant('Z'));
	printf("1: %d\n", isletter('1'));
}
Task: Pythagorean triples

C: #include <stdio.h>
#include <stdlib.h>
 
typedef unsigned long long xint;
typedef unsigned long ulong;

inline ulong gcd(ulong m, ulong n)
{
    ulong t;
    while (n) { t = n; n = m % n; m = t; }
    return m;
}
 
int main()
{
    ulong a, b, c, pytha = 0, prim = 0, max_p = 100;
    xint aa, bb, cc;

    for (a = 1; a <= max_p / 3; a++) {
        aa = (xint)a * a;
        printf("a = %lu\r", a); 
        fflush(stdout);

        
        for (b = a + 1; b < max_p/2; b++) {
            bb = (xint)b * b;
            for (c = b + 1; c < max_p/2; c++) {
                cc = (xint)c * c;
                if (aa + bb < cc) break;
                if (a + b + c > max_p) break;

                if (aa + bb == cc) {
                    pytha++;
                    if (gcd(a, b) == 1) prim++;
                }
            }
        }
    }
 
    printf("Up to %lu, there are %lu triples, of which %lu are primitive\n",
        max_p, pytha, prim);

    return 0;
}
Task: Call a foreign-language function

C: 



#include <stdio.h>

void sayHello(char* name){
    printf("Hello %s!\n", name);
}

int doubleNum(int num){
    return num * 2;
}
Task: Extensible prime generator

C: #include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

#define CHUNK_BYTES (32 << 8)
#define CHUNK_SIZE (CHUNK_BYTES << 6)

int field[CHUNK_BYTES];
#define GET(x) (field[(x)>>6] &  1<<((x)>>1&31))
#define SET(x) (field[(x)>>6] |= 1<<((x)>>1&31))

typedef unsigned uint;
typedef struct {
        uint *e;
        uint cap, len;
} uarray;
uarray primes, offset;

void push(uarray *a, uint n)
{
        if (a->len >= a->cap) {
                if (!(a->cap *= 2)) a->cap = 16;
                a->e = realloc(a->e, sizeof(uint) * a->cap);
        }
        a->e[a->len++] = n;
}

uint low;
void init(void)
{
        uint p, q;

        unsigned char f[1<<16];
        memset(f, 0, sizeof(f));
        push(&primes, 2);
        push(&offset, 0);
        for (p = 3; p < 1<<16; p += 2) {
                if (f[p]) continue;
                for (q = p*p; q < 1<<16; q += 2*p) f[q] = 1;
                push(&primes, p);
                push(&offset, q);
        }
        low = 1<<16;
}

void sieve(void)
{
        uint i, p, q, hi, ptop;
        if (!low) init();

        memset(field, 0, sizeof(field));

        hi = low + CHUNK_SIZE;
        ptop = sqrt(hi) * 2 + 1;

        for (i = 1; (p = primes.e[i]*2) < ptop; i++) {
                for (q = offset.e[i] - low; q < CHUNK_SIZE; q += p)
                        SET(q);
                offset.e[i] = q + low;
        }

        for (p = 1; p < CHUNK_SIZE; p += 2)
                if (!GET(p)) push(&primes, low + p);

        low = hi;
}

int main(void)
{
        uint i, p, c;

        while (primes.len < 20) sieve();
        printf("First 20:");
        for (i = 0; i < 20; i++)
                printf(" %u", primes.e[i]);
        putchar('\n');

        while (primes.e[primes.len-1] < 150) sieve();
        printf("Between 100 and 150:");
        for (i = 0; i < primes.len; i++) {
                if ((p = primes.e[i]) >= 100 && p < 150)
                        printf(" %u", primes.e[i]);
        }
        putchar('\n');

        while (primes.e[primes.len-1] < 8000) sieve();
        for (i = c = 0; i < primes.len; i++)
                if ((p = primes.e[i]) >= 7700 && p < 8000) c++;
        printf("%u primes between 7700 and 8000\n", c);

        for (c = 10; c <= 100000000; c *= 10) {
                while (primes.len < c) sieve();
                printf("%uth prime: %u\n", c, primes.e[c-1]);
        }

        return 0;
}
Task: Gray code

C: int gray_encode(int n) {
    return n ^ (n >> 1);
}

int gray_decode(int n) {
    int p = n;
    while (n >>= 1) p ^= n;
    return p;
}