WeixiangYan/CodeTransOcean huggingface dataset:
Task: Jaro similarity


C++: #include <algorithm>
#include <iostream>
#include <string>

double jaro(const std::string s1, const std::string s2) {
    const uint l1 = s1.length(), l2 = s2.length();
    if (l1 == 0)
        return l2 == 0 ? 1.0 : 0.0;
    const uint match_distance = std::max(l1, l2) / 2 - 1;
    bool s1_matches[l1];
    bool s2_matches[l2];
    std::fill(s1_matches, s1_matches + l1, false);
    std::fill(s2_matches, s2_matches + l2, false);
    uint matches = 0;
    for (uint i = 0; i < l1; i++)
    {
        const int end = std::min(i + match_distance + 1, l2);
        for (int k = std::max(0u, i - match_distance); k < end; k++)
            if (!s2_matches[k] && s1[i] == s2[k])
            {
                s1_matches[i] = true;
                s2_matches[k] = true;
                matches++;
                break;
            }
    }
    if (matches == 0)
        return 0.0;
    double t = 0.0;
    uint k = 0;
    for (uint i = 0; i < l1; i++)
        if (s1_matches[i])
        {
            while (!s2_matches[k]) k++;
            if (s1[i] != s2[k]) t += 0.5;
            k++;
        }

    const double m = matches;
    return (m / l1 + m / l2 + (m - t) / m) / 3.0;
}

int main() {
    using namespace std;
    cout << jaro("MARTHA", "MARHTA") << endl;
    cout << jaro("DIXON", "DICKSONX") << endl;
    cout << jaro("JELLYFISH", "SMELLYFISH") << endl;
    return 0;
}



Go: package main

import "fmt"

func jaro(str1, str2 string) float64 {
    if len(str1) == 0 && len(str2) == 0 {
        return 1
    }
    if len(str1) == 0 || len(str2) == 0 {
        return 0
    }
    match_distance := len(str1)
    if len(str2) > match_distance {
        match_distance = len(str2)
    }
    match_distance = match_distance/2 - 1
    str1_matches := make([]bool, len(str1))
    str2_matches := make([]bool, len(str2))
    matches := 0.
    transpositions := 0.
    for i := range str1 {
        start := i - match_distance
        if start < 0 {
            start = 0
        }
        end := i + match_distance + 1
        if end > len(str2) {
            end = len(str2)
        }
        for k := start; k < end; k++ {
            if str2_matches[k] {
                continue
            }
            if str1[i] != str2[k] {
                continue
            }
            str1_matches[i] = true
            str2_matches[k] = true
            matches++
            break
        }
    }
    if matches == 0 {
        return 0
    }
    k := 0
    for i := range str1 {
        if !str1_matches[i] {
            continue
        }
        for !str2_matches[k] {
            k++
        }
        if str1[i] != str2[k] {
            transpositions++
        }
        k++
    }
    transpositions /= 2
    return (matches/float64(len(str1)) +
        matches/float64(len(str2)) +
        (matches-transpositions)/matches) / 3
}

func main() {
    fmt.Printf("%f\n", jaro("MARTHA", "MARHTA"))
    fmt.Printf("%f\n", jaro("DIXON", "DICKSONX"))
    fmt.Printf("%f\n", jaro("JELLYFISH", "SMELLYFISH"))
}
Task: Fairshare between two and more


C++: #include <iostream>
#include <vector>

int turn(int base, int n) {
    int sum = 0;
    while (n != 0) {
        int rem = n % base;
        n = n / base;
        sum += rem;
    }
    return sum % base;
}

void fairshare(int base, int count) {
    printf("Base %2d:", base);
    for (int i = 0; i < count; i++) {
        int t = turn(base, i);
        printf(" %2d", t);
    }
    printf("\n");
}

void turnCount(int base, int count) {
    std::vector<int> cnt(base, 0);

    for (int i = 0; i < count; i++) {
        int t = turn(base, i);
        cnt[t]++;
    }

    int minTurn = INT_MAX;
    int maxTurn = INT_MIN;
    int portion = 0;
    for (int i = 0; i < base; i++) {
        if (cnt[i] > 0) {
            portion++;
        }
        if (cnt[i] < minTurn) {
            minTurn = cnt[i];
        }
        if (cnt[i] > maxTurn) {
            maxTurn = cnt[i];
        }
    }

    printf("  With %d people: ", base);
    if (0 == minTurn) {
        printf("Only %d have a turn\n", portion);
    } else if (minTurn == maxTurn) {
        printf("%d\n", minTurn);
    } else {
        printf("%d or %d\n", minTurn, maxTurn);
    }
}

int main() {
    fairshare(2, 25);
    fairshare(3, 25);
    fairshare(5, 25);
    fairshare(11, 25);

    printf("How many times does each get a turn in 50000 iterations?\n");
    turnCount(191, 50000);
    turnCount(1377, 50000);
    turnCount(49999, 50000);
    turnCount(50000, 50000);
    turnCount(50001, 50000);

    return 0;
}



Go: package main

import (
    "fmt"
    "sort"
    "strconv"
    "strings"
)

func fairshare(n, base int) []int {
    res := make([]int, n)
    for i := 0; i < n; i++ {
        j := i
        sum := 0
        for j > 0 {
            sum += j % base
            j /= base
        }
        res[i] = sum % base
    }
    return res
}

func turns(n int, fss []int) string {
    m := make(map[int]int)
    for _, fs := range fss {
        m[fs]++
    }
    m2 := make(map[int]int)
    for _, v := range m {
        m2[v]++
    }
    res := []int{}
    sum := 0
    for k, v := range m2 {
        sum += v
        res = append(res, k)
    }
    if sum != n {
        return fmt.Sprintf("only %d have a turn", sum)
    }
    sort.Ints(res)
    res2 := make([]string, len(res))
    for i := range res {
        res2[i] = strconv.Itoa(res[i])
    }
    return strings.Join(res2, " or ")
}

func main() {
    for _, base := range []int{2, 3, 5, 11} {
        fmt.Printf("%2d : %2d\n", base, fairshare(25, base))
    }
    fmt.Println("\nHow many times does each get a turn in 50000 iterations?")
    for _, base := range []int{191, 1377, 49999, 50000, 50001} {
        t := turns(base, fairshare(50000, base))
        fmt.Printf("  With %d people: %s\n", base, t)
    }
}
Task: Trabb Pardo–Knuth algorithm


C++: #include <iostream>
#include <cmath>
#include <vector>
#include <algorithm>
#include <iomanip>

int main( ) {
   std::vector<double> input( 11 ) , results( 11 ) ;
   std::cout << "Please enter 11 numbers!\n" ;
   for ( int i = 0 ; i < input.size( ) ; i++ ) 
      std::cin >> input[i];
      
   std::transform( input.begin( ) , input.end( ) , results.begin( ) ,
	 [ ]( double n )-> double { return sqrt( abs( n ) ) + 5 * pow( n , 3 ) ; } ) ;
   for ( int i = 10 ; i > -1 ; i-- ) {
      std::cout << "f( " << std::setw( 3 ) << input[ i ] << " ) : " ; 
      if ( results[ i ] > 400 ) 
	 std::cout << "too large!" ;
      else 
	 std::cout << results[ i ] << " !" ;
      std::cout << std::endl ;
   }
   return 0 ;
}



Go: package main

import (
    "fmt"
    "log"
    "math"
)

func main() {
    
    fmt.Print("Enter 11 numbers: ")
    
    var s [11]float64
    for i := 0; i < 11; {
        if n, _ := fmt.Scan(&s[i]); n > 0 {
            i++
        }
    }
    
    for i, item := range s[:5] {
        s[i], s[10-i] = s[10-i], item
    }
    
    for _, item := range s {
        if result, overflow := f(item); overflow {
            
            log.Printf("f(%g) overflow", item)
        } else {
            
            fmt.Printf("f(%g) = %g\n", item, result)
        }
    }
}

func f(x float64) (float64, bool) {
    result := math.Sqrt(math.Abs(x)) + 5*x*x*x
    return result, result > 400
}
Task: Middle three digits


C++: #include <iostream>

std::string middleThreeDigits(int n)
{
    auto number = std::to_string(std::abs(n));
    auto length = number.size();

    if (length < 3) {
        return "less than three digits";
    } else if (length % 2 == 0) {
        return "even number of digits";
    } else {
        return number.substr(length / 2 - 1, 3);
    }
}

int main()
{
    auto values {123, 12345, 1234567, 987654321, 10001,
                 -10001, -123, -100, 100, -12345,
                 1, 2, -1, -10, 2002, -2002, 0};

    for (auto&& v : values) {
        std::cout << "middleThreeDigits(" << v << "): " <<
                     middleThreeDigits(v) << "\n";
    }
}



Go: package m3

import (
    "errors"
    "strconv"
)

var (
    ErrorLT3  = errors.New("N of at least three digits required.")
    ErrorEven = errors.New("N with odd number of digits required.")
)

func Digits(i int) (string, error) {
    if i < 0 {
        i = -i
    }
    if i < 100 {
        return "", ErrorLT3
    }
    s := strconv.Itoa(i)
    if len(s)%2 == 0 {
        return "", ErrorEven
    }
    m := len(s) / 2
    return s[m-1 : m+2], nil
}
Task: Sequence_ smallest number with exactly n divisors


C++: #include <iostream>

#define MAX 15

using namespace std;

int count_divisors(int n) {
    int count = 0;
    for (int i = 1; i * i <= n; ++i) {
        if (!(n % i)) {
            if (i == n / i)
                count++;
            else
                count += 2;
        }
    }
    return count;
}

int main() {
    int i, k, n, seq[MAX];
    for (i = 0; i < MAX; ++i) seq[i] = 0;
    cout << "The first " << MAX << " terms of the sequence are:" << endl;
    for (i = 1, n = 0; n <  MAX; ++i) {
        k = count_divisors(i);
        if (k <= MAX && seq[k - 1] == 0) {
            seq[k - 1] = i;
            ++n;
        }
    }
    for (i = 0; i < MAX; ++i) cout << seq[i] << " ";
    cout << endl;
    return 0;
}



Go: package main

import "fmt"

func countDivisors(n int) int {
    count := 0
    for i := 1; i*i <= n; i++ {
        if n%i == 0 {
            if i == n/i {
                count++
            } else {
                count += 2
            }
        }
    }
    return count
}

func main() {
    const max = 15
    seq := make([]int, max)
    fmt.Println("The first", max, "terms of the sequence are:")
    for i, n := 1, 0; n < max; i++ {
        if k := countDivisors(i); k <= max && seq[k-1] == 0 {
            seq[k-1] = i
            n++
        }
    }
    fmt.Println(seq)
}
Task: Pancake numbers


C++: #include <iomanip>
#include <iostream>

int pancake(int n) {
    int gap = 2, sum = 2, adj = -1;
    while (sum < n) {
        adj++;
        gap = gap * 2 - 1;
        sum += gap;
    }
    return n + adj;
}

int main() {
    for (int i = 0; i < 4; i++) {
        for (int j = 1; j < 6; j++) {
            int n = i * 5 + j;
            std::cout << "p(" << std::setw(2) << n << ") = " << std::setw(2) << pancake(n) << "  ";
        }
        std::cout << '\n';
    }
    return 0;
}



Go: package main

import "fmt"

func pancake(n int) int {
    gap, sum, adj := 2, 2, -1
    for sum < n {
        adj++
        gap = gap*2 - 1
        sum += gap
    }
    return n + adj
}

func main() {
    for i := 0; i < 4; i++ {
        for j := 1; j < 6; j++ {
            n := i*5 + j
            fmt.Printf("p(%2d) = %2d  ", n, pancake(n))
        }
        fmt.Println()
    }
}
Task: Topswops


C++: #include <iostream>
#include <vector>
#include <numeric>
#include <algorithm>

int topswops(int n) {
  std::vector<int> list(n);
  std::iota(std::begin(list), std::end(list), 1);
  int max_steps = 0;
  do {
    auto temp_list = list;
    for (int steps = 1; temp_list[0] != 1; ++steps) {
      std::reverse(std::begin(temp_list), std::begin(temp_list) + temp_list[0]);
      if (steps > max_steps) max_steps = steps;
    }
  } while (std::next_permutation(std::begin(list), std::end(list)));
  return max_steps;
}

int main() {
  for (int i = 1; i <= 10; ++i) {
    std::cout << i << ": " << topswops(i) << std::endl;
  }
  return 0;
}



Go: 


package main

import "fmt"

const ( 
    maxn = 10 
    maxl = 50 
)

func main() {
    for i := 1; i <= maxn; i++ {
        fmt.Printf("%d: %d\n", i, steps(i))
    }
}

func steps(n int) int {
    var a, b [maxl][maxn + 1]int
    var x [maxl]int
    a[0][0] = 1
    var m int
    for l := 0; ; {
        x[l]++
        k := int(x[l])
        if k >= n {
            if l <= 0 {
                break
            }
            l--
            continue
        }
        if a[l][k] == 0 {
            if b[l][k+1] != 0 {
                continue
            }
        } else if a[l][k] != k+1 {
            continue
        }
        a[l+1] = a[l]
        for j := 1; j <= k; j++ {
            a[l+1][j] = a[l][k-j]
        }
        b[l+1] = b[l]
        a[l+1][0] = k + 1
        b[l+1][k+1] = 1
        if l > m-1 {
            m = l + 1
        }
        l++
        x[l] = 0
    }
    return m
}
Task: Rate counter


C++: #include <iostream>
#include <ctime>



class CRateState
{
protected:
    time_t m_lastFlush;
    time_t m_period;
    size_t m_tickCount;
public:
    CRateState(time_t period);
    void Tick();
};

CRateState::CRateState(time_t period) : m_lastFlush(std::time(NULL)),
                                        m_period(period),
                                        m_tickCount(0)
{ }

void CRateState::Tick()
{
    m_tickCount++;

    time_t now = std::time(NULL);

    if((now - m_lastFlush) >= m_period)
    {
        
        size_t tps = 0.0;
        if(m_tickCount > 0)
            tps = m_tickCount / (now - m_lastFlush);

        std::cout << tps << " tics per second" << std::endl;

        
        m_tickCount = 0;
        m_lastFlush = now;
    }
}



void something_we_do()
{
    
    
    
    
    
    
    
    volatile size_t anchor = 0;
    for(size_t x = 0; x < 0xffff; ++x)
    {
        anchor = x;
    }
}

int main()
{
    time_t start = std::time(NULL);

    CRateState rateWatch(5);

    
    for(time_t latest = start; (latest - start) < 20; latest = std::time(NULL))
    {
        
        something_we_do();

        
        rateWatch.Tick();
    }

    return 0;
}



Go: package main

import (
    "fmt"
    "math/rand"
    "time"
)


type rateStateS struct {
    lastFlush time.Time
    period    time.Duration
    tickCount int
}

func ticRate(pRate *rateStateS) {
    pRate.tickCount++
    now := time.Now()
    if now.Sub(pRate.lastFlush) >= pRate.period {
        
        tps := 0.
        if pRate.tickCount > 0 {
            tps = float64(pRate.tickCount) / now.Sub(pRate.lastFlush).Seconds()
        }
        fmt.Println(tps, "tics per second.")

        
        pRate.tickCount = 0
        pRate.lastFlush = now
    }
}

func somethingWeDo() {
    time.Sleep(time.Duration(9e7 + rand.Int63n(2e7))) 
}

func main() {
    start := time.Now()

    rateWatch := rateStateS{
        lastFlush: start,
        period:    5 * time.Second,
    }

    
    latest := start
    for latest.Sub(start) < 20*time.Second {
        somethingWeDo()
        ticRate(&rateWatch)
        latest = time.Now()
    }
}
Task: Sequence_ smallest number greater than previous term with exactly n divisors


C++: #include <iostream>

#define MAX 15

using namespace std;

int count_divisors(int n) {
    int count = 0;
    for (int i = 1; i * i <= n; ++i) {
        if (!(n % i)) {
            if (i == n / i)
                count++;
            else
                count += 2;
        }
    }
    return count;
}

int main() {
    cout << "The first " << MAX << " terms of the sequence are:" << endl;
    for (int i = 1, next = 1; next <= MAX; ++i) {
        if (next == count_divisors(i)) {           
            cout << i << " ";
            next++;
        }
    }
    cout << endl;
    return 0;
}



Go: package main

import "fmt"

func countDivisors(n int) int {
    count := 0
    for i := 1; i*i <= n; i++ {
        if n%i == 0 {
            if i == n/i {
                count++
            } else {
                count += 2
            }
        }
    }
    return count
}

func main() {
    const max = 15
    fmt.Println("The first", max, "terms of the sequence are:")
    for i, next := 1, 1; next <= max; i++ {
        if next == countDivisors(i) {
            fmt.Printf("%d ", i)
            next++
        }
    }
    fmt.Println()
}
Task: Odd word problem


C++: #include <iostream>
#include <cctype>
#include <functional>

using namespace std;

bool odd()
{
  function<void ()> prev = []{};
  while(true) {
    int c = cin.get();
    if (!isalpha(c)) {
      prev();
      cout.put(c);
      return c != '.';
    }
    prev = [=] { cout.put(c); prev();  };
  }
}

bool even() 
{
  while(true) {
    int c;
    cout.put(c = cin.get());
    if (!isalpha(c)) return c != '.';
  }
}


int main()
{
  bool e = false;
  while( e ? odd() : even() ) e = !e;
  return 0;
}



Go: package main

import (
    "bytes"
    "fmt"
    "io"
    "os"
    "unicode"
)

func main() {
    owp(os.Stdout, bytes.NewBufferString("what,is,the;meaning,of:life."))
    fmt.Println()
    owp(os.Stdout, bytes.NewBufferString("we,are;not,in,kansas;any,more."))
    fmt.Println()
}

func owp(dst io.Writer, src io.Reader) {
    byte_in := func () byte {
        bs := make([]byte, 1)
        src.Read(bs)
        return bs[0]
    }
    byte_out := func (b byte) { dst.Write([]byte{b}) }    
    var odd func() byte
    odd = func() byte {
        s := byte_in()
        if unicode.IsPunct(rune(s)) {
            return s
        }
        b := odd()
        byte_out(s)
        return b
    }
    for {
        for {
            b := byte_in()
            byte_out(b)
            if b == '.' {
                return
            }
            if unicode.IsPunct(rune(b)) {
                break
            }
        }
        b := odd()
        byte_out(b)
        if b == '.' {
            return
        }
    }
}
Task: Include a file


C++: 
import <iostream>;



Go: 
package main

import "fmt"

func hello() {
    fmt.Println("Hello from main.go")
}

func main() {
    hello()
    hello2()
}
Task: Stern-Brocot sequence


C++: #include <iostream>
#include <iomanip>
#include <algorithm>
#include <vector>

unsigned gcd( unsigned i, unsigned j ) {
    return i ? i < j ? gcd( j % i, i ) : gcd( i % j, j ) : j;
}
void createSequence( std::vector<unsigned>& seq, int c ) {
    if( 1500 == seq.size() ) return;
    unsigned t = seq.at( c ) + seq.at( c + 1 );
    seq.push_back( t );
    seq.push_back( seq.at( c + 1 ) );
    createSequence( seq, c + 1 );
}
int main( int argc, char* argv[] ) {
    std::vector<unsigned> seq( 2, 1 );
    createSequence( seq, 0 );

    std::cout << "First fifteen members of the sequence:\n    ";
    for( unsigned x = 0; x < 15; x++ ) {
        std::cout << seq[x] << " ";    
    }

    std::cout << "\n\n";    
    for( unsigned x = 1; x < 11; x++ ) {
        std::vector<unsigned>::iterator i = std::find( seq.begin(), seq.end(), x );
        if( i != seq.end() ) {
            std::cout << std::setw( 3 ) << x << " is at pos. #" << 1 + distance( seq.begin(), i ) << "\n";
        }
    }

    std::cout << "\n";
    std::vector<unsigned>::iterator i = std::find( seq.begin(), seq.end(), 100 );
    if( i != seq.end() ) {
        std::cout << 100 << " is at pos. #" << 1 + distance( seq.begin(), i ) << "\n";
    }

    std::cout << "\n";
    unsigned g;
    bool f = false;
    for( int x = 0, y = 1; x < 1000; x++, y++ ) {
        g =  gcd( seq[x], seq[y] );
	if( g != 1 ) f = true;
        std::cout << std::setw( 4 ) << x + 1 << ": GCD (" << seq[x] << ", " 
                  << seq[y] << ") = " << g << ( g != 1 ? " <-- ERROR\n" : "\n" );
    }
    std::cout << "\n" << ( f ? "THERE WERE ERRORS --- NOT ALL GCDs ARE '1'!" : "CORRECT: ALL GCDs ARE '1'!" ) << "\n\n";
    return 0;
}



Go: package main

import (
    "fmt"

    "sternbrocot"
)

func main() {
    
    
    g := sb.Generator()

    
    fmt.Println("First 15:")
    for i := 1; i <= 15; i++ {
        fmt.Printf("%2d:  %d\n", i, g())
    }

    
    
    s := sb.New()
    fmt.Println("First 15:", s.FirstN(15))

    
    for _, x := range []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 100} {
        fmt.Printf("%3d at 1-based index %d\n", x, 1+s.Find(x))
    }

    
    fmt.Println("1-based indexes: gcd")
    for n, f := range s.FirstN(1000)[:999] {
        g := gcd(f, (*s)[n+1])
        fmt.Printf("%d,%d: gcd(%d, %d) = %d\n", n+1, n+2, f, (*s)[n+1], g)
        if g != 1 {
            panic("oh no!")
            return
        }
    }
}


func gcd(x, y int) int {
    for y != 0 {
        x, y = y, x%y
    }
    return x
}
Task: Numeric error propagation


C++: #pragma once

#include <cmath>
#include <string>
#include <sstream>
#include <iomanip>

class Approx {
public:
    Approx(double _v, double _s = 0.0) : v(_v), s(_s) {}

    operator std::string() const {
        std::ostringstream os("");
        os << std::setprecision(15) << v << " ±" << std::setprecision(15) << s << std::ends;
        return os.str();
    }

    Approx operator +(const Approx& a) const { return Approx(v + a.v, sqrt(s * s + a.s * a.s)); }
    Approx operator +(double d) const { return Approx(v + d, s); }
    Approx operator -(const Approx& a) const { return Approx(v - a.v, sqrt(s * s + a.s * a.s)); }
    Approx operator -(double d) const { return Approx(v - d, s); }

    Approx operator *(const Approx& a) const {
        const double t = v * a.v;
        return Approx(v, sqrt(t * t * s * s / (v * v) + a.s * a.s / (a.v * a.v)));
    }

    Approx operator *(double d) const { return Approx(v * d, fabs(d * s)); }

    Approx operator /(const Approx& a) const {
        const double t = v / a.v;
        return Approx(t, sqrt(t * t * s * s / (v * v) + a.s * a.s / (a.v * a.v)));
    }

    Approx operator /(double d) const { return Approx(v / d, fabs(d * s)); }

    Approx pow(double d) const {
        const double t = ::pow(v, d);
        return Approx(t, fabs(t * d * s / v));
    }

private:
    double v, s;
};



Go: package main

import (
    "fmt"
    "math"
)




type unc struct {
    n float64 
    s float64 
}


func newUnc(n, s float64) *unc {
    return &unc{n, s * s}
}



func (z *unc) errorTerm() float64 {
    return math.Sqrt(z.s)
}









func (z *unc) addC(a *unc, c float64) *unc {
    *z = *a
    z.n += c
    return z
}

func (z *unc) subC(a *unc, c float64) *unc {
    *z = *a
    z.n -= c
    return z
}

func (z *unc) addU(a, b *unc) *unc {
    z.n = a.n + b.n
    z.s = a.s + b.s
    return z
}
func (z *unc) subU(a, b *unc) *unc {
    z.n = a.n - b.n
    z.s = a.s + b.s
    return z
}


func (z *unc) mulC(a *unc, c float64) *unc {
    z.n = a.n * c
    z.s = a.s * c * c
    return z
}

func (z *unc) divC(a *unc, c float64) *unc {
    z.n = a.n / c
    z.s = a.s / (c * c)
    return z
}

func (z *unc) mulU(a, b *unc) *unc {
    prod := a.n * b.n
    z.n, z.s = prod, prod*prod*(a.s/(a.n*a.n)+b.s/(b.n*b.n))
    return z
}

func (z *unc) divU(a, b *unc) *unc {
    quot := a.n / b.n
    z.n, z.s = quot, quot*quot*(a.s/(a.n*a.n)+b.s/(b.n*b.n))
    return z
}


func (z *unc) expC(a *unc, c float64) *unc {
    f := math.Pow(a.n, c)
    g := f * c / a.n
    z.n = f
    z.s = a.s * g * g
    return z
}

func main() {
    x1 := newUnc(100, 1.1)
    x2 := newUnc(200, 2.2)
    y1 := newUnc(50, 1.2)
    y2 := newUnc(100, 2.3)
    var d, d2 unc
    d.expC(d.addU(d.expC(d.subU(x1, x2), 2), d2.expC(d2.subU(y1, y2), 2)), .5)
    fmt.Println("d:    ", d.n)
    fmt.Println("error:", d.errorTerm())
}