WeixiangYan/CodeTransOcean huggingface dataset:
Task: Chernick's Carmichael numbers

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

typedef unsigned long long int u64;

#define TRUE 1
#define FALSE 0

int primality_pretest(u64 k) {
    if (!(k %  3) || !(k %  5) || !(k %  7) || !(k % 11) || !(k % 13) || !(k % 17) || !(k % 19) || !(k % 23)) return (k <= 23);
    return TRUE;
}

int probprime(u64 k, mpz_t n) {
    mpz_set_ui(n, k);
    return mpz_probab_prime_p(n, 0);
}

int is_chernick(int n, u64 m, mpz_t z) {
    u64 t = 9 * m;
    if (primality_pretest(6 * m + 1) == FALSE) return FALSE;
    if (primality_pretest(12 * m + 1) == FALSE) return FALSE;
    for (int i = 1; i <= n - 2; i++) if (primality_pretest((t << i) + 1) == FALSE) return FALSE;
    if (probprime(6 * m + 1, z) == FALSE) return FALSE;
    if (probprime(12 * m + 1, z) == FALSE) return FALSE;
    for (int i = 1; i <= n - 2; i++) if (probprime((t << i) + 1, z) == FALSE) return FALSE;
    return TRUE;
}

int main(int argc, char const *argv[]) {
    mpz_t z;
    mpz_inits(z, NULL);

    for (int n = 3; n <= 10; n ++) {
        u64 multiplier = (n > 4) ? (1 << (n - 4)) : 1;

        if (n > 5) multiplier *= 5;

        for (u64 k = 1; ; k++) {
            u64 m = k * multiplier;

            if (is_chernick(n, m, z) == TRUE) {
                printf("a(%d) has m = %llu\n", n, m);
                break;
            }
        }
    }

    return 0;
}







Python: 



from sympy import isprime



def primality_pretest(k):
    if not (k % 3) or not (k % 5) or not (k % 7) or not (k % 11) or not(k % 13) or not (k % 17) or not (k % 19) or not (k % 23):
        return (k <= 23)
        
    return True

def is_chernick(n, m):

    t = 9 * m
    
    if not primality_pretest(6 * m + 1):
        return False
        
    if not primality_pretest(12 * m + 1):
        return False
        
    for i in range(1,n-1):
        if not primality_pretest((t << i) + 1):
            return False
        
    if not isprime(6 * m + 1):
        return False
        
    if not isprime(12 * m + 1):
        return False
        
    for i in range(1,n - 1):
        if not isprime((t << i) + 1):
            return False
        
    return True
    
for n in range(3,10):

    if n > 4:
        multiplier = 1 << (n - 4)
    else:
        multiplier = 1
    
    if n > 5:
        multiplier *= 5
        
        
    k = 1
    
    while True:
        m = k * multiplier
        
        if is_chernick(n, m): 
            print("a("+str(n)+") has m = "+str(m))
            break
            
        k += 1
Task: Tau function

C: #include <stdio.h>


unsigned int divisor_count(unsigned int n) {
    unsigned int total = 1;
    
    for (; (n & 1) == 0; n >>= 1) {
        ++total;
    }
    
    for (unsigned int p = 3; p * p <= n; p += 2) {
        unsigned int count = 1;
        for (; n % p == 0; n /= p) {
            ++count;
        }
        total *= count;
    }
    
    if (n > 1) {
        total *= 2;
    }
    return total;
}

int main() {
    const unsigned int limit = 100;
    unsigned int n;

    printf("Count of divisors for the first %d positive integers:\n", limit);
    for (n = 1; n <= limit; ++n) {
        printf("%3d", divisor_count(n));
        if (n % 20 == 0) {
            printf("\n");
        }
    }

    return 0;
}







Python: def factorize(n):
    assert(isinstance(n, int))
    if n < 0: 
        n = -n 
    if n < 2: 
        return 
    k = 0 
    while 0 == n%2: 
        k += 1 
        n //= 2 
    if 0 < k: 
        yield (2,k) 
    p = 3 
    while p*p <= n: 
        k = 0 
        while 0 == n%p: 
            k += 1 
            n //= p 
        if 0 < k: 
            yield (p,k)
        p += 2 
    if 1 < n: 
        yield (n,1) 

def tau(n): 
    assert(n != 0) 
    ans = 1 
    for (p,k) in factorize(n): 
        ans *= 1 + k
    return ans

if __name__ == "__main__":
    print(*map(tau, range(1, 101)))
Task: Sequence of primorial primes

C: #include <gmp.h>

int main(void)
{
    mpz_t p, s;
    mpz_init_set_ui(p, 1);
    mpz_init_set_ui(s, 1);

    for (int n = 1, i = 0; i < 20; n++) {
        mpz_nextprime(s, s);
        mpz_mul(p, p, s);

        mpz_add_ui(p, p, 1);
        if (mpz_probab_prime_p(p, 25)) {
            mpz_sub_ui(p, p, 1);
            gmp_printf("%d\n", n);
            i++;
            continue;
        }

        mpz_sub_ui(p, p, 2);
        if (mpz_probab_prime_p(p, 25)) {
            mpz_add_ui(p, p, 1);
            gmp_printf("%d\n", n);
            i++;
            continue;
        }

        mpz_add_ui(p, p, 1);
    }

    mpz_clear(s);
    mpz_clear(p);
}







Python: import pyprimes

def primorial_prime(_pmax=500):
    isprime = pyprimes.isprime
    n, primo = 0, 1
    for prime in pyprimes.nprimes(_pmax):
        n, primo = n+1, primo * prime
        if isprime(primo-1) or isprime(primo+1):
            yield n
        
if __name__ == '__main__':
    
    pyprimes.warn_probably = False  
    for i, n in zip(range(20), primorial_prime()):
        print('Primorial prime %2i at primorial index: %3i' % (i+1, n))
Task: Bioinformatics_base count

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

typedef struct genome{
    char* strand;
    int length;
    struct genome* next;
}genome;

genome* genomeData;
int totalLength = 0, Adenine = 0, Cytosine = 0, Guanine = 0, Thymine = 0;

int numDigits(int num){
    int len = 1;

    while(num>10){
        num = num/10;
        len++;
    }

    return len;
}

void buildGenome(char str[100]){
    int len = strlen(str),i;
    genome *genomeIterator, *newGenome; 

    totalLength += len;

    for(i=0;i<len;i++){
        switch(str[i]){
            case 'A': Adenine++;
                break;
            case 'T': Thymine++;
                break;
            case 'C': Cytosine++;
                break;
            case 'G': Guanine++;
                break;
        };
    }

    if(genomeData==NULL){
        genomeData = (genome*)malloc(sizeof(genome));

        genomeData->strand = (char*)malloc(len*sizeof(char));
        strcpy(genomeData->strand,str);
        genomeData->length = len;

        genomeData->next = NULL;
    }

    else{
        genomeIterator = genomeData;

        while(genomeIterator->next!=NULL)
            genomeIterator = genomeIterator->next;

        newGenome = (genome*)malloc(sizeof(genome));

        newGenome->strand = (char*)malloc(len*sizeof(char));
        strcpy(newGenome->strand,str);
        newGenome->length = len;

        newGenome->next = NULL;
        genomeIterator->next = newGenome;
    }
}

void printGenome(){
    genome* genomeIterator = genomeData;

    int width = numDigits(totalLength), len = 0;

    printf("Sequence:\n");

    while(genomeIterator!=NULL){
        printf("\n%*d%3s%3s",width+1,len,":",genomeIterator->strand);
        len += genomeIterator->length;

        genomeIterator = genomeIterator->next;
    }

    printf("\n\nBase Count\n----------\n\n");

    printf("%3c%3s%*d\n",'A',":",width+1,Adenine);
    printf("%3c%3s%*d\n",'T',":",width+1,Thymine);
    printf("%3c%3s%*d\n",'C',":",width+1,Cytosine);
    printf("%3c%3s%*d\n",'G',":",width+1,Guanine);
    printf("\n%3s%*d\n","Total:",width+1,Adenine + Thymine + Cytosine + Guanine);

    free(genomeData);
}

int main(int argc,char** argv)
{
    char str[100];
    int counter = 0, len;
    
    if(argc!=2){
        printf("Usage : %s <Gene file name>\n",argv[0]);
        return 0;
    }

    FILE *fp = fopen(argv[1],"r");

    while(fscanf(fp,"%s",str)!=EOF)
        buildGenome(str);
    fclose(fp);

    printGenome();

    return 0;
}







Python: from collections import Counter

def basecount(dna):
    return sorted(Counter(dna).items())

def seq_split(dna, n=50):
    return [dna[i: i+n] for i in range(0, len(dna), n)]

def seq_pp(dna, n=50):
    for i, part in enumerate(seq_split(dna, n)):
        print(f"{i*n:>5}: {part}")
    print("\n  BASECOUNT:")
    tot = 0
    for base, count in basecount(dna):
        print(f"    {base:>3}: {count}")
        tot += count
    base, count = 'TOT', tot
    print(f"    {base:>3}= {count}")
    
if __name__ == '__main__':
    print("SEQUENCE:")
    sequence = 
    seq_pp(sequence)
Task: Factorions

C: #include <stdio.h>

int main() {    
    int n, b, d;
    unsigned long long i, j, sum, fact[12];
    
    fact[0] = 1;
    for (n = 1; n < 12; ++n) {
        fact[n] = fact[n-1] * n;
    }

    for (b = 9; b <= 12; ++b) {
        printf("The factorions for base %d are:\n", b);
        for (i = 1; i < 1500000; ++i) {
            sum = 0;
            j = i;
            while (j > 0) {
                d = j % b;
                sum += fact[d];
                j /= b;
            }
            if (sum == i) printf("%llu ", i);
        }
        printf("\n\n");
    }
    return 0;
}







Python: fact = [1] 
for n in range(1, 12):
    fact.append(fact[n-1] * n)

for b in range(9, 12+1):
    print(f"The factorions for base {b} are:")
    for i in range(1, 1500000):
        fact_sum = 0
        j = i
        while j > 0:
            d = j % b
            fact_sum += fact[d]
            j = j//b
        if fact_sum == i:
            print(i, end=" ")
    print("\n")
Task: Logistic curve fitting in epidemiology

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

const double K = 7.8e9;
const int n0 = 27;
const double actual[] = {
    27, 27, 27, 44, 44, 59, 59, 59, 59, 59, 59, 59, 59, 60, 60,
    61, 61, 66, 83, 219, 239, 392, 534, 631, 897, 1350, 2023, 2820,
    4587, 6067, 7823, 9826, 11946, 14554, 17372, 20615, 24522, 28273,
    31491, 34933, 37552, 40540, 43105, 45177, 60328, 64543, 67103,
    69265, 71332, 73327, 75191, 75723, 76719, 77804, 78812, 79339,
    80132, 80995, 82101, 83365, 85203, 87024, 89068, 90664, 93077,
    95316, 98172, 102133, 105824, 109695, 114232, 118610, 125497,
    133852, 143227, 151367, 167418, 180096, 194836, 213150, 242364,
    271106, 305117, 338133, 377918, 416845, 468049, 527767, 591704,
    656866, 715353, 777796, 851308, 928436, 1000249, 1082054, 1174652
};
const size_t actual_size = sizeof(actual) / sizeof(double);

double f(double r) {
    double sq = 0;
    size_t i;
    for (i = 0; i < actual_size; ++i) {
        double eri = exp(r * i);
        double guess = (n0 * eri) / (1 + n0 * (eri - 1) / K);
        double diff = guess - actual[i];
        sq += diff * diff;
    }
    return sq;
}

double solve(double (*fn)(double), double guess, double epsilon) {
    double delta, f0, factor;
    for (delta = guess ? guess : 1, f0 = fn(guess), factor = 2;
        delta > epsilon && guess != guess - delta;
        delta *= factor) {
        double nf = (*fn)(guess - delta);
        if (nf < f0) {
            f0 = nf;
            guess -= delta;
        } else {
            nf = fn(guess + delta);
            if (nf < f0) {
                f0 = nf;
                guess += delta;
            } else {
                factor = 0.5;
            }
        }
    }
    return guess;
}

double solve_default(double (*fn)(double)) {
    return solve(fn, 0.5, 0);
}

int main() {
    double r = solve_default(f);
    double R0 = exp(12 * r);
    printf("r = %f, R0 = %f\n", r, R0);
    return 0;
}







Python: import numpy as np
import scipy.optimize as opt

n0, K = 27, 7_800_000_000

def f(t, r):
    return (n0 * np.exp(r * t)) / (( 1 + n0 * (np.exp(r * t) - 1) / K))

y = [
27, 27, 27, 44, 44, 59, 59, 59, 59, 59, 59, 59, 59, 60, 60,
61, 61, 66, 83, 219, 239, 392, 534, 631, 897, 1350, 2023,
2820, 4587, 6067, 7823, 9826, 11946, 14554, 17372, 20615,
24522, 28273, 31491, 34933, 37552, 40540, 43105, 45177,
60328, 64543, 67103, 69265, 71332, 73327, 75191, 75723,
76719, 77804, 78812, 79339, 80132, 80995, 82101, 83365,
85203, 87024, 89068, 90664, 93077, 95316, 98172, 102133,
105824, 109695, 114232, 118610, 125497, 133852, 143227,
151367, 167418, 180096, 194836, 213150, 242364, 271106,
305117, 338133, 377918, 416845, 468049, 527767, 591704,
656866, 715353, 777796, 851308, 928436, 1000249, 1082054,
1174652,
]
x = np.linspace(0.0, 96, 97)

r, cov = opt.curve_fit(f, x, y, [0.5])


print("The r for the world Covid-19 data is:", r,
    ", with covariance of", cov)   
print("The calculated R0 is then", np.exp(12 * r))
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;
}







Python: def merge_list(a, b):
	out = []
	while len(a) and len(b):
		if a[0] < b[0]:
			out.append(a.pop(0))
		else:
			out.append(b.pop(0))
	out += a
	out += b
	return out

def strand(a):
	i, s = 0, [a.pop(0)]
	while i < len(a):
		if a[i] > s[-1]:
			s.append(a.pop(i))
		else:
			i += 1
	return s

def strand_sort(a):
	out = strand(a)
	while len(a):
		out = merge_list(out, strand(a))
	return out

print strand_sort([1, 6, 3, 2, 1, 7, 5, 3])
Task: Additive primes

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

void memoizeIsPrime( bool * result, const int N )
{
    result[2] = true;
    result[3] = true;
    int prime[N];
    prime[0] = 3;
    int end = 1;
    for (int n = 5; n < N; n += 2)
    {
        bool n_is_prime = true;
        for (int i = 0; i < end; ++i)
        {
            const int PRIME = prime[i];
            if (n % PRIME == 0)
            {
                n_is_prime = false;
                break;
            }
            if (PRIME * PRIME > n)
            {
                break;
            }
        }
        if (n_is_prime)
        {
            prime[end++] = n;
            result[n] = true;
        }
    }
}

int sumOfDecimalDigits( int n )
{
    int sum = 0;
    while (n > 0)
    {
        sum += n % 10;
        n /= 10;
    }
    return sum;
}

int main( void )
{
    const int N = 500;

    printf( "Rosetta Code: additive primes less than %d:\n", N );

    bool is_prime[N];
    memset( is_prime, 0, sizeof(is_prime) );
    memoizeIsPrime( is_prime, N );

    printf( "   2" );
    int count = 1;
    for (int i = 3; i < N; i += 2)
    {
        if (is_prime[i] && is_prime[sumOfDecimalDigits( i )])
        {
            printf( "%4d", i );
            ++count;
            if ((count % 10) == 0)
            {
                printf( "\n" );
            }
        }
    }
    printf( "\nThose were %d additive primes.\n", count );
    return 0;
}







Python: def is_prime(n: int) -> bool:
    if n <= 3:
        return n > 1
    if n % 2 == 0 or n % 3 == 0:
        return False
    i = 5
    while i ** 2 <= n:
        if n % i == 0 or n % (i + 2) == 0:
            return False
        i += 6
    return True

def digit_sum(n: int) -> int:
    sum = 0
    while n > 0:
        sum += n % 10
        n //= 10
    return sum

def main() -> None:
    additive_primes = 0
    for i in range(2, 500):
        if is_prime(i) and is_prime(digit_sum(i)):
            additive_primes += 1
            print(i, end=" ")
    print(f"\nFound {additive_primes} additive primes less than 500")

if __name__ == "__main__":
    main()
Task: Inverted syntax

C: #include <stdio.h>
#include <stdlib.h>
#define otherwise       do { register int _o = 2; do { switch (_o) {  case 1:
#define given(Mc)       ;case 0: break; case 2: _o = !!(Mc); continue; } break; } while (1); } while (0)


int foo() { return 1; }

main()
{
        int a = 0;

        otherwise  a = 4 given (foo());
        printf("%d\n", a);
        exit(0);
}







Python: x = truevalue if condition else falsevalue
Task: Perfect totient numbers

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

long totient(long n){
	long tot = n,i;
	
	for(i=2;i*i<=n;i+=2){
		if(n%i==0){
			while(n%i==0)
				n/=i;
			tot-=tot/i;
		}
		
		if(i==2)
			i=1;
	}
	
	if(n>1)
		tot-=tot/n;
	
	return tot;
}

long* perfectTotients(long n){
	long *ptList = (long*)malloc(n*sizeof(long)), m,count=0,sum,tot;
	
	for(m=1;count<n;m++){
		 tot = m;
		 sum = 0;
        while(tot != 1){
            tot = totient(tot);
            sum += tot;
        }
        if(sum == m)
			ptList[count++] = m;
        }
		
		return ptList;
}

long main(long argC, char* argV[])
{
	long *ptList,i,n;
	
	if(argC!=2)
		printf("Usage : %s <number of perfect Totient numbers required>",argV[0]);
	else{
		n = atoi(argV[1]);
		
		ptList = perfectTotients(n);
		
		printf("The first %d perfect Totient numbers are : \n[",n);
		
		for(i=0;i<n;i++)
			printf(" %d,",ptList[i]);
		printf("\b]");
	}
	
	return 0;
}







Python: from math import gcd
from functools import lru_cache
from itertools import islice, count

@lru_cache(maxsize=None)
def  φ(n):
    return sum(1 for k in range(1, n + 1) if gcd(n, k) == 1)

def perfect_totient():
    for n0 in count(1):
        parts, n = 0, n0
        while n != 1:
            n = φ(n)
            parts += n
        if parts == n0:
            yield n0
        

if __name__ == '__main__':
    print(list(islice(perfect_totient(), 20)))
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;
}







Python: class Delegator:
   def __init__(self):
      self.delegate = None
   def operation(self):
       if hasattr(self.delegate, 'thing') and callable(self.delegate.thing):
          return self.delegate.thing()
       return 'default implementation'

class Delegate:
   def thing(self):
      return 'delegate implementation'

if __name__ == '__main__':

   
   a = Delegator()
   assert a.operation() == 'default implementation'

   
   a.delegate = 'A delegate may be any object'
   assert a.operation() == 'default implementation'

   
   a.delegate = Delegate()
   assert a.operation() == 'delegate implementation'
Task: Sum of divisors

C: #include <stdio.h>


unsigned int divisor_sum(unsigned int n) {
    unsigned int total = 1, power = 2;
    unsigned int p;
    
    for (; (n & 1) == 0; power <<= 1, n >>= 1) {
        total += power;
    }
    
    for (p = 3; p * p <= n; p += 2) {
        unsigned int sum = 1;
        for (power = p; n % p == 0; power *= p, n /= p) {
            sum += power;
        }
        total *= sum;
    }
    
    if (n > 1) {
        total *= n + 1;
    }
    return total;
}

int main() {
    const unsigned int limit = 100;
    unsigned int n;
    printf("Sum of divisors for the first %d positive integers:\n", limit);
    for (n = 1; n <= limit; ++n) {
        printf("%4d", divisor_sum(n));
        if (n % 10 == 0) {
            printf("\n");
        }
    }
    return 0;
}







Python: def factorize(n):
    assert(isinstance(n, int))
    if n < 0: 
        n = -n 
    if n < 2: 
        return 
    k = 0 
    while 0 == n%2: 
        k += 1 
        n //= 2 
    if 0 < k: 
        yield (2,k) 
    p = 3 
    while p*p <= n: 
        k = 0 
        while 0 == n%p: 
            k += 1 
            n //= p 
        if 0 < k: 
            yield (p,k)
        p += 2 
    if 1 < n: 
        yield (n,1) 

def sum_of_divisors(n): 
    assert(n != 0) 
    ans = 1 
    for (p,k) in factorize(n): 
        ans *= (pow(p,k+1) - 1)//(p-1) 
    return ans 
    
if __name__ == "__main__":
    print([sum_of_divisors(n) for n in range(1,101)])
Task: Enforced immutability

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







Python: >>> s = "Hello"
>>> s[0] = "h"

Traceback (most recent call last):
  File "<pyshell
    s[0] = "h"
TypeError: 'str' object does not support item assignment
Task: Spiral matrix

C: #include <stdio.h>
#include <stdlib.h>
 
#define valid(i, j) 0 <= i && i < m && 0 <= j && j < n && !s[i][j]
int main(int c, char **v)
{
	int i, j, m = 0, n = 0;
 
	
	if (c >= 2) m = atoi(v[1]);
	if (c >= 3) n = atoi(v[2]);
	if (m <= 0) m = 5;
	if (n <= 0) n = m;
 
	int **s = calloc(1, sizeof(int *) * m + sizeof(int) * m * n);
	s[0] = (int*)(s + m);
	for (i = 1; i < m; i++) s[i] = s[i - 1] + n;
 
	int dx = 1, dy = 0, val = 0, t;
	for (i = j = 0; valid(i, j); i += dy, j += dx ) {
		for (; valid(i, j); j += dx, i += dy)
			s[i][j] = ++val;
 
		j -= dx; i -= dy;
		t = dy; dy = dx; dx = -t;
	}

	for (t = 2; val /= 10; t++);

	for(i = 0; i < m; i++)
		for(j = 0; j < n || !putchar('\n'); j++)
			printf("%*d", t, s[i][j]);

	return 0;
}







Python: def spiral(n):
    dx,dy = 1,0            
    x,y = 0,0              
    myarray = [[None]* n for j in range(n)]
    for i in xrange(n**2):
        myarray[x][y] = i
        nx,ny = x+dx, y+dy
        if 0<=nx<n and 0<=ny<n and myarray[nx][ny] == None:
            x,y = nx,ny
        else:
            dx,dy = -dy,dx
            x,y = x+dx, y+dy
    return myarray

def printspiral(myarray):
    n = range(len(myarray))
    for y in n:
        for x in n:
            print "%2i" % myarray[x][y],
        print

printspiral(spiral(5))
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;
}







Python: import ctypes
libc = ctypes.CDLL("/lib/libc.so.6")
libc.strcmp("abc", "def")     
libc.strcmp("hello", "hello")