WeixiangYan/CodeTransOcean huggingface dataset:
Task: Sorting algorithms_Strand sort

C: #include <stdio.h>

typedef struct node_t *node, node_t;
struct node_t { int v; node next; };
typedef struct { node head, tail; } slist;

void push(slist *l, node e) {
	if (!l->head) l->head = e;
	if (l->tail)  l->tail->next = e;
	l->tail = e;
}

node removehead(slist *l) {
	node e = l->head;
	if (e) {
		l->head = e->next;
		e->next = 0;
	}
	return e;
}

void join(slist *a, slist *b) {
	push(a, b->head);
	a->tail = b->tail;
}

void merge(slist *a, slist *b) {
	slist r = {0};
	while (a->head && b->head)
		push(&r, removehead(a->head->v <= b->head->v ? a : b));

	join(&r, a->head ? a : b);
	*a = r;
	b->head = b->tail = 0;
}

void sort(int *ar, int len)
{
	node_t all[len];

	
	for (int i = 0; i < len; i++)
		all[i].v = ar[i], all[i].next = i < len - 1 ? all + i + 1 : 0;

	slist list = {all, all + len - 1}, rem, strand = {0},  res = {0};

	for (node e = 0; list.head; list = rem) {
		rem.head = rem.tail = 0;
		while ((e = removehead(&list)))
			push((!strand.head || e->v >= strand.tail->v) ? &strand : &rem, e);

		merge(&res, &strand);
	}

	
	for (int i = 0; res.head; i++, res.head = res.head->next)
		ar[i] = res.head->v;
}

void show(const char *title, int *x, int len)
{
	printf("%s ", title);
	for (int i = 0; i < len; i++)
		printf("%3d ", x[i]);
	putchar('\n');
}

int main(void)
{
	int x[] = {-2,0,-2,5,5,3,-1,-3,5,5,0,2,-4,4,2};
#	define SIZE sizeof(x)/sizeof(int)

	show("before sort:", x, SIZE);
	sort(x, sizeof(x)/sizeof(int));
	show("after sort: ", x, SIZE);

	return 0;
}






PHP: $lst = new SplDoublyLinkedList();
foreach (array(1,20,64,72,48,75,96,55,42,74) as $v)
    $lst->push($v);
foreach (strandSort($lst) as $v)
    echo "$v ";

function strandSort(SplDoublyLinkedList $lst) {
    $result = new SplDoublyLinkedList();
    while (!$lst->isEmpty()) {
        $sorted = new SplDoublyLinkedList();
        $remain = new SplDoublyLinkedList();
        $sorted->push($lst->shift());
        foreach ($lst as $item) {
            if ($sorted->top() <= $item) {
                $sorted->push($item);
            } else {
                $remain->push($item);
            }
        }
        $result = _merge($sorted, $result);
        $lst = $remain;
    }
    return $result;
}

function _merge(SplDoublyLinkedList $left, SplDoublyLinkedList $right) {
    $res = new SplDoublyLinkedList();
    while (!$left->isEmpty() && !$right->isEmpty()) {
        if ($left->bottom() <= $right->bottom()) {
            $res->push($left->shift());
        } else {
            $res->push($right->shift());
        }
    }
    foreach ($left as $v)  $res->push($v);
    foreach ($right as $v) $res->push($v);
    return $res;
}
Task: Delegates

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

typedef const char * (*Responder)( int p1);

typedef struct sDelegate {
    Responder operation;
} *Delegate;


Delegate NewDelegate( Responder rspndr )
{
    Delegate dl = malloc(sizeof(struct sDelegate));
    dl->operation = rspndr;
    return dl;
}


const char *DelegateThing(Delegate dl, int p1)
{
    return  (dl->operation)? (*dl->operation)(p1) : NULL;
}


typedef struct sDelegator {
    int     param;
    char    *phrase;
    Delegate delegate;
} *Delegator;

const char * defaultResponse( int p1)
{
    return "default implementation";
}

static struct sDelegate defaultDel = { &defaultResponse };


Delegator NewDelegator( int p, char *phrase)
{
    Delegator d  = malloc(sizeof(struct sDelegator));
    d->param = p;
    d->phrase = phrase;
    d->delegate = &defaultDel;	
    return d;
}


const char *Delegator_Operation( Delegator theDelegator, int p1, Delegate delroy)
{
    const char *rtn;
    if (delroy) {
        rtn = DelegateThing(delroy, p1);
        if (!rtn) {			
            rtn = DelegateThing(theDelegator->delegate, p1);
        }
    }
    else 		
        rtn = DelegateThing(theDelegator->delegate, p1);

    printf("%s\n", theDelegator->phrase );
    return rtn;
}


const char *thing1( int p1)
{
    printf("We're in thing1 with value %d\n" , p1);
    return "delegate implementation";
}

int main()
{
    Delegate del1 = NewDelegate(&thing1);
    Delegate del2 = NewDelegate(NULL);
    Delegator theDelegator = NewDelegator( 14, "A stellar vista, Baby.");

    printf("Delegator returns %s\n\n", 
            Delegator_Operation( theDelegator, 3, NULL));
    printf("Delegator returns %s\n\n", 
            Delegator_Operation( theDelegator, 3, del1));
    printf("Delegator returns %s\n\n",
            Delegator_Operation( theDelegator, 3, del2));
    return 0;
}






PHP: class Delegator {
  function __construct() {
    $this->delegate = NULL ;
  }
  function operation() {
    if(method_exists($this->delegate, "thing"))
      return $this->delegate->thing() ;
    return 'default implementation' ;
  }
}

class Delegate {
  function thing() {
    return 'Delegate Implementation' ;
  }
}

$a = new Delegator() ;
print "{$a->operation()}\n" ;

$a->delegate = 'A delegate may be any object' ;
print "{$a->operation()}\n" ;

$a->delegate = new Delegate() ;
print "{$a->operation()}\n" ;
Task: Enforced immutability

C: #define PI      3.14159265358979323
#define MINSIZE 10
#define MAXSIZE 100






PHP: define("PI", 3.14159265358);
define("MSG", "Hello World");
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;
}






PHP: $ffi = FFI::cdef("char *_strdup(const char *strSource);", "msvcrt.dll");

$cstr = $ffi->_strdup("success");
$str = FFI::string($cstr);
echo $str;
FFI::free($cstr);
Task: Knuth's algorithm S

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

struct s_env {
    unsigned int n, i;
    size_t size;
    void *sample;
};

void s_of_n_init(struct s_env *s_env, size_t size, unsigned int n)
{
    s_env->i = 0;
    s_env->n = n;
    s_env->size = size;
    s_env->sample = malloc(n * size);
}

void sample_set_i(struct s_env *s_env, unsigned int i, void *item)
{
    memcpy(s_env->sample + i * s_env->size, item, s_env->size);
}

void *s_of_n(struct s_env *s_env, void *item)
{
    s_env->i++;
    if (s_env->i <= s_env->n)
        sample_set_i(s_env, s_env->i - 1, item);
    else if ((rand() % s_env->i) < s_env->n)
        sample_set_i(s_env, rand() % s_env->n, item);
    return s_env->sample;
}

int *test(unsigned int n, int *items_set, unsigned int num_items)
{
    int i;
    struct s_env s_env;
    s_of_n_init(&s_env, sizeof(items_set[0]), n);
    for (i = 0; i < num_items; i++) {
        s_of_n(&s_env, (void *) &items_set[i]);
    }
    return (int *)s_env.sample;
}

int main()
{
    unsigned int i, j;
    unsigned int n = 3;
    unsigned int num_items = 10;
    unsigned int *frequencies;
    int *items_set;
    srand(time(NULL));
    items_set = malloc(num_items * sizeof(int));
    frequencies = malloc(num_items * sizeof(int));
    for (i = 0; i < num_items; i++) {
        items_set[i] = i;
        frequencies[i] = 0;
    }
    for (i = 0; i < 100000; i++) {
        int *res = test(n, items_set, num_items);
        for (j = 0; j < n; j++) {
            frequencies[res[j]]++;
        }
	free(res);
    }
    for (i = 0; i < num_items; i++) {
        printf(" %d", frequencies[i]);
    }
    puts("");
    return 0;
}






PHP: <?php
function s_of_n_creator($n) {
    $sample = array();
    $i = 0;
    return function($item) use (&$sample, &$i, $n) {
        $i++;
        if ($i <= $n) {

            $sample[] = $item;
        } else if (rand(0, $i-1) < $n) {

            $sample[rand(0, $n-1)] = $item;
        }
        return $sample;
    };
}

$items = range(0, 9);

for ($trial = 0; $trial < 100000; $trial++) {
    $s_of_n = s_of_n_creator(3);
    foreach ($items as $item)
        $sample = $s_of_n($item);
    foreach ($sample as $s)
        $bin[$s]++;
}
print_r($bin);
?>
Task: Command-line arguments

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

int main(int argc, char* argv[])
{
  int i;
  (void) printf("This program is named %s.\n", argv[0]);
  for (i = 1; i < argc; ++i)
    (void) printf("the argument #%d is %s\n", i, argv[i]);
  return EXIT_SUCCESS;
}






PHP: <?php
$program_name = $argv[0];
$second_arg = $argv[2];
$all_args_without_program_name = array_shift($argv);
Task: Array concatenation

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

#define ARRAY_CONCAT(TYPE, A, An, B, Bn) \
  (TYPE *)array_concat((const void *)(A), (An), (const void *)(B), (Bn), sizeof(TYPE));

void *array_concat(const void *a, size_t an,
                   const void *b, size_t bn, size_t s)
{
  char *p = malloc(s * (an + bn));
  memcpy(p, a, an*s);
  memcpy(p + an*s, b, bn*s);
  return p;
}


const int a[] = { 1, 2, 3, 4, 5 };
const int b[] = { 6, 7, 8, 9, 0 };

int main(void)
{
  unsigned int i;

  int *c = ARRAY_CONCAT(int, a, 5, b, 5);

  for(i = 0; i < 10; i++)
    printf("%d\n", c[i]);

  free(c);
  return EXIT_SUCCCESS;
}






PHP: $arr1 = array(1, 2, 3);
$arr2 = array(4, 5, 6);
$arr3 = array_merge($arr1, $arr2);
Task: User input_Text

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

int main(void)
{
    
    char str[BUFSIZ];
    puts("Enter a string: ");
    fgets(str, sizeof(str), stdin);

    
    long num;
    char buf[BUFSIZ];
    do
    {
        puts("Enter 75000: ");
        fgets(buf, sizeof(buf), stdin);
        num = strtol(buf, NULL, 10);
    } while (num != 75000);

    return EXIT_SUCCESS;
}






PHP: #!/usr/bin/php
<?php
$string = fgets(STDIN);
$integer = (int) fgets(STDIN);
Task: First-class functions

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

typedef double (*Class2Func)(double);
 

double functionA( double v)
{
   return v*v*v;
}
double functionB(double v)
{
   return exp(log(v)/3);
}
 

double Function1( Class2Func f2, double val )
{
    return f2(val);
}
 

Class2Func WhichFunc( int idx)
{
   return (idx < 4) ? &functionA : &functionB;
}
 

Class2Func funcListA[] = {&functionA, &sin, &cos, &tan };
Class2Func funcListB[] = {&functionB, &asin, &acos, &atan };
 

double InvokeComposed( Class2Func f1, Class2Func f2, double val )
{
   return f1(f2(val));
}
 
typedef struct sComposition {
   Class2Func f1;
   Class2Func f2;
} *Composition;
 
Composition Compose( Class2Func f1, Class2Func f2)
{
   Composition comp = malloc(sizeof(struct sComposition));
   comp->f1 = f1;
   comp->f2 = f2;
   return comp;
}
 
double CallComposed( Composition comp, double val )
{
    return comp->f1( comp->f2(val) );
}

 
int main(int argc, char *argv[])
{
   int ix;
   Composition c;
 
   printf("Function1(functionA, 3.0) = %f\n", Function1(WhichFunc(0), 3.0));
 
   for (ix=0; ix<4; ix++) {
       c = Compose(funcListA[ix], funcListB[ix]);
       printf("Compostion %d(0.9) = %f\n", ix, CallComposed(c, 0.9));
   }
 
   return 0;
}






PHP: $compose = function ($f, $g) {
    return function ($x) use ($f, $g) {
        return $f($g($x));
    };
};

$fn  = array('sin', 'cos', function ($x) { return pow($x, 3); });
$inv = array('asin', 'acos', function ($x) { return pow($x, 1/3); });

for ($i = 0; $i < 3; $i++) {
    $f = $compose($inv[$i], $fn[$i]);
    echo $f(0.5), PHP_EOL;
}
Task: Proper divisors

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

int proper_divisors(const int n, bool print_flag)
{
    int count = 0;

    for (int i = 1; i < n; ++i) {
        if (n % i == 0) {
            count++;
            if (print_flag)
                printf("%d ", i);
        }
    }

    if (print_flag)
        printf("\n");

    return count;
}

int main(void)
{
    for (int i = 1; i <= 10; ++i) {
        printf("%d: ", i);
        proper_divisors(i, true);
    }

    int max = 0;
    int max_i = 1;

    for (int i = 1; i <= 20000; ++i) {
        int v = proper_divisors(i, false);
        if (v >= max) {
            max = v;
            max_i = i;
        }
    }

    printf("%d with %d divisors\n", max_i, max);
    return 0;
}






PHP: <?php
function ProperDivisors($n) {
  yield 1;
  $large_divisors = [];
  for ($i = 2; $i <= sqrt($n); $i++) {
    if ($n % $i == 0) {
      yield $i;
      if ($i*$i != $n) {
        $large_divisors[] = $n / $i;
      }
    }
  }
  foreach (array_reverse($large_divisors) as $i) {
    yield $i;
  }
}

assert([1, 2, 4, 5, 10, 20, 25, 50] ==
        iterator_to_array(ProperDivisors(100)));

foreach (range(1, 10) as $n) {
  echo "$n =>";
  foreach (ProperDivisors($n) as $divisor) {
    echo " $divisor";
  }
  echo "\n";
}

$divisorsCount = [];
for ($i = 1; $i < 20000; $i++) {
  $divisorsCount[sizeof(iterator_to_array(ProperDivisors($i)))][] = $i;
}
ksort($divisorsCount);

echo "Numbers with most divisors: ", implode(", ", end($divisorsCount)), ".\n";
echo "They have ", key($divisorsCount), " divisors.\n";
Task: Regular expressions

C: #include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <regex.h>
#include <string.h>

int main()
{
   regex_t preg;
   regmatch_t substmatch[1];
   const char *tp = "string$";
   const char *t1 = "this is a matching string";
   const char *t2 = "this is not a matching string!";
   const char *ss = "istyfied";
   
   regcomp(&preg, "string$", REG_EXTENDED);
   printf("'%s' %smatched with '%s'\n", t1,
                                        (regexec(&preg, t1, 0, NULL, 0)==0) ? "" : "did not ", tp);
   printf("'%s' %smatched with '%s'\n", t2,
                                        (regexec(&preg, t2, 0, NULL, 0)==0) ? "" : "did not ", tp);
   regfree(&preg);
   
   regcomp(&preg, "a[a-z]+", REG_EXTENDED);
   if ( regexec(&preg, t1, 1, substmatch, 0) == 0 )
   {
      
      char *ns = malloc(substmatch[0].rm_so + 1 + strlen(ss) +
                        (strlen(t1) - substmatch[0].rm_eo) + 2);
      memcpy(ns, t1, substmatch[0].rm_so+1);
      memcpy(&ns[substmatch[0].rm_so], ss, strlen(ss));
      memcpy(&ns[substmatch[0].rm_so+strlen(ss)], &t1[substmatch[0].rm_eo],
                strlen(&t1[substmatch[0].rm_eo]));
      ns[ substmatch[0].rm_so + strlen(ss) +
          strlen(&t1[substmatch[0].rm_eo]) ] = 0;
      printf("mod string: '%s'\n", ns);
      free(ns); 
   } else {
      printf("the string '%s' is the same: no matching!\n", t1);
   }
   regfree(&preg);
   
   return 0;
}






PHP: $string = 'I am a string';
# Test
if (preg_match('/string$/', $string))
{
    echo "Ends with 'string'\n";
}
# Replace
$string = preg_replace('/\ba\b/', 'another', $string);
echo "Found 'a' and replace it with 'another', resulting in this string: $string\n";
Task: Hash from two arrays

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

#define KeyType const char *
#define ValType int

#define HASH_SIZE 4096


unsigned strhashkey( const char * key, int max)
{
    unsigned h=0;
    unsigned hl, hr;

    while(*key) {
        h += *key;
        hl= 0x5C5 ^ (h&0xfff00000 )>>18;
        hr =(h&0x000fffff );
        h = hl ^ hr ^ *key++;
    }
    return h % max;
}

typedef struct sHme {
    KeyType    key;
    ValType    value;
    struct sHme  *link;
} *MapEntry;

typedef struct he {
    MapEntry  first, last;
} HashElement;

HashElement hash[HASH_SIZE];
    
typedef void (*KeyCopyF)(KeyType *kdest, KeyType ksrc);
typedef void (*ValCopyF)(ValType *vdest, ValType vsrc);
typedef unsigned (*KeyHashF)( KeyType key, int upperBound );
typedef int (*KeyCmprF)(KeyType key1, KeyType key2);

void HashAddH( KeyType key, ValType value,
        KeyCopyF copyKey, ValCopyF copyVal, KeyHashF hashKey, KeyCmprF keySame )
{
    unsigned hix = (*hashKey)(key, HASH_SIZE);
    MapEntry m_ent;

    for (m_ent= hash[hix].first;
            m_ent && !(*keySame)(m_ent->key,key); m_ent=m_ent->link);
    if (m_ent) {
        (*copyVal)(&m_ent->value, value);
    }
    else {
        MapEntry last;
        MapEntry hme = malloc(sizeof(struct sHme));
        (*copyKey)(&hme->key, key);
        (*copyVal)(&hme->value, value);
        hme->link = NULL;
        last = hash[hix].last;
        if (last) {

            last->link = hme;
        }
        else
            hash[hix].first = hme;
        hash[hix].last = hme;
    }
}

int HashGetH(ValType *val, KeyType key, KeyHashF hashKey, KeyCmprF keySame )
{
    unsigned hix = (*hashKey)(key, HASH_SIZE);
    MapEntry m_ent;
    for (m_ent= hash[hix].first;
            m_ent && !(*keySame)(m_ent->key,key); m_ent=m_ent->link);
    if (m_ent) {
        *val = m_ent->value;
    }
    return (m_ent != NULL);
}

void copyStr(const char**dest, const char *src)
{
    *dest = strdup(src);
}
void copyInt( int *dest, int src)
{
    *dest = src;
}
int strCompare( const char *key1, const char *key2)
{
    return strcmp(key1, key2) == 0;
}
    
void HashAdd( KeyType key, ValType value )
{
    HashAddH( key, value, &copyStr, &copyInt, &strhashkey, &strCompare);
}

int HashGet(ValType *val, KeyType key)
{
    return HashGetH( val, key, &strhashkey, &strCompare);
}

int main() 
{
    static const char * keyList[] = {"red","orange","yellow","green", "blue", "violet" };
    static int valuList[] = {1,43,640, 747, 42, 42};
    int ix;

    for (ix=0; ix<6; ix++) {
        HashAdd(keyList[ix], valuList[ix]);
    }
    return 0;
}






PHP: $keys = array('a', 'b', 'c');
$values = array(1, 2, 3);
$hash = array_combine($keys, $values);
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;
}






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: Arrays

C:  char foo()
{
char array[5] = {3,6,9,12,15};
return array[2];
}






PHP: $NumberArray = array(0, 1, 2, 3, 4, 5, 6);
$LetterArray = array("a", "b", "c", "d", "e", "f");
$simpleForm = ['apple', 'orange'];
Task: Sierpinski carpet

C: #include <stdio.h>

int main()
{
	int i, j, dim, d;
	int depth = 3;

	for (i = 0, dim = 1; i < depth; i++, dim *= 3);

	for (i = 0; i < dim; i++) {
		for (j = 0; j < dim; j++) {
			for (d = dim / 3; d; d /= 3)
				if ((i % (d * 3)) / d == 1 && (j % (d * 3)) / d == 1)
					break;
			printf(d ? "  " : "##");
		}
		printf("\n");
	}

	return 0;
}






PHP: <?php

function isSierpinskiCarpetPixelFilled($x, $y) {
    while (($x > 0) or ($y > 0)) {
        if (($x % 3 == 1) and ($y % 3 == 1)) {
            return false;
        }
        $x /= 3;
        $y /= 3;
    }
    return true;
}

function sierpinskiCarpet($order) {
    $size = pow(3, $order);
    for ($y = 0 ; $y < $size ; $y++) {
        for ($x = 0 ; $x < $size ; $x++) {
            echo isSierpinskiCarpetPixelFilled($x, $y) ? '#' : ' ';
        }
        echo PHP_EOL;
    }
}

for ($order = 0 ; $order <= 3 ; $order++) {
    echo 'N=', $order, PHP_EOL;
    sierpinskiCarpet($order);
    echo PHP_EOL;
}
Task: Sorting algorithms_Bogosort

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

bool is_sorted(int *a, int n)
{
  while ( --n >= 1 ) {
    if ( a[n] < a[n-1] ) return false;
  }
  return true;
}

void shuffle(int *a, int n)
{
  int i, t, r;
  for(i=0; i < n; i++) {
    t = a[i];
    r = rand() % n;
    a[i] = a[r];
    a[r] = t;
  }
}

void bogosort(int *a, int n)
{
  while ( !is_sorted(a, n) ) shuffle(a, n);
}

int main()
{
  int numbers[] = { 1, 10, 9,  7, 3, 0 };
  int i;

  bogosort(numbers, 6);
  for (i=0; i < 6; i++) printf("%d ", numbers[i]);
  printf("\n");
}






PHP: function bogosort($l) {
    while (!in_order($l))
        shuffle($l);
    return $l;
}

function in_order($l) {
    for ($i = 1; $i < count($l); $i++)
        if ($l[$i] < $l[$i-1])
            return FALSE;
    return TRUE;
}
Task: Sequence of non-squares

C: #include <math.h>
#include <stdio.h>
#include <assert.h>

int nonsqr(int n) {
    return n + (int)(0.5 + sqrt(n));
    
}

int main() {
    int i;
    
    
    for (i = 1; i < 23; i++)
        printf("%d ", nonsqr(i));
    printf("\n");
    
    
    for (i = 1; i < 1000000; i++) {
        double j = sqrt(nonsqr(i));
        assert(j != floor(j));
    }
    return 0;
}






PHP: <?php

	for($i=1;$i<=22;$i++){
		echo($i + floor(1/2 + sqrt($i)) . "\n");
	}

	$found_square=False;
	for($i=1;$i<=1000000;$i++){
		$non_square=$i + floor(1/2 + sqrt($i));
		if(sqrt($non_square)==intval(sqrt($non_square))){
			$found_square=True;
		}
	}
	echo("\n");
	if($found_square){
		echo("Found a square number, so the formula does not always work.");
	} else {
		echo("Up to 1000000, found no square number in the sequence!");
	}
?>
Task: Substring

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


void putm(char* string, size_t m)
{
    while(*string && m--)
        putchar(*string++);
}

int main(void)
{

    char string[] = 
        "Programs for other encodings (such as 8-bit ASCII, or EUC-JP)."

    int n = 3;
    int m = 4;
    char knownCharacter = '(';
    char knownSubstring[] = "encodings";

    putm(string+n-1, m );                       putchar('\n');
    puts(string+n+1);                           putchar('\n');
    putm(string, strlen(string)-1);             putchar('\n');
    putm(strchr(string, knownCharacter), m );   putchar('\n');
    putm(strstr(string, knownSubstring), m );   putchar('\n');

    return EXIT_SUCCESS;
}






PHP: <?php
$str = 'abcdefgh';
$n = 2;
$m = 3;
echo substr($str, $n, $m), "\n"; //cde
echo substr($str, $n), "\n"; //cdefgh
echo substr($str, 0, -1), "\n"; //abcdefg
echo substr($str, strpos($str, 'd'), $m), "\n"; //def
echo substr($str, strpos($str, 'de'), $m), "\n"; //def
?>
Task: Leap year

C: #include <stdio.h>

int is_leap_year(unsigned year)
{
    return !(year & (year % 100 ? 3 : 15));
}

int main(void)
{
    const unsigned test_case[] = {
        1900, 1994, 1996, 1997, 2000, 2024, 2025, 2026, 2100
    };
    const unsigned n = sizeof test_case / sizeof test_case[0];

    for (unsigned i = 0; i != n; ++i) {
        unsigned year = test_case[i];
        printf("%u is %sa leap year.\n", year, is_leap_year(year) ? "" : "not ");
    }
    return 0;
}






PHP: <?php
function isLeapYear($year) {
    if ($year % 100 == 0) {
        return ($year % 400 == 0);
    }
    return ($year % 4 == 0);
}
Task: Sorting algorithms_Shell sort

C: #include <stdio.h>

void shell_sort (int *a, int n) {
    int h, i, j, t;
    for (h = n; h /= 2;) {
        for (i = h; i < n; i++) {
            t = a[i];
            for (j = i; j >= h && t < a[j - h]; j -= h) {
                a[j] = a[j - h];
            }
            a[j] = t;
        }
    }
}

int main (int ac, char **av) {
    int a[] = {4, 65, 2, -31, 0, 99, 2, 83, 782, 1};
    int n = sizeof a / sizeof a[0];
    int i;
    for (i = 0; i < n; i++)
        printf("%d%s", a[i], i == n - 1 ? "\n" : " ");
    shell_sort(a, n);
    for (i = 0; i < n; i++)
        printf("%d%s", a[i], i == n - 1 ? "\n" : " ");
    return 0;
}






PHP: function shellSort($arr)
{
	$inc = round(count($arr)/2);
	while($inc > 0)
	{
		for($i = $inc; $i < count($arr);$i++){
			$temp = $arr[$i];
			$j = $i;
			while($j >= $inc && $arr[$j-$inc] > $temp)
			{
				$arr[$j] = $arr[$j - $inc];
				$j -= $inc;
			}
			$arr[$j] = $temp;
		}
		$inc = round($inc/2.2);
	}
	return $arr;
}
Task: Letter frequency

C: 
int frequency[26];
int ch;
FILE* txt_file = fopen ("a_text_file.txt", "rt");


for (ch = 0; ch < 26; ch++)
    frequency[ch] = 0;

while (1) {
    ch = fgetc(txt_file);
    if (ch == EOF) break; 

    
    if ('a' <= ch && ch <= 'z')      
        frequency[ch-'a']++;
    else if ('A' <= ch && ch <= 'Z') 
        frequency[ch-'A']++;
}






PHP: <?php
print_r(array_count_values(str_split(file_get_contents($argv[1]))));
?>