Negative Base Conversion

Though, First time it may be a surprising fact that, "NEGATIVE BASE!!!", But it really exists. :)
Here goes it.Click Here for details.

NegaTernary(-3) Base conversion python implementation:

def negaternary(i):
    digits = []
    while i != 0:
        i, remainder = divmod(i, -3)
        if remainder < 0:
            i, remainder = i + 1, remainder + 3
        digits.insert(0, str (remainder))
    return ''.join(digits)

And Here is NegaBinary(-2) Base conversion in C:

#include<stdio.h>
int main()
{
	char a[100];
	int num,temp;

	while(~scanf("%d",&num))
	{
	while(num!=0)
	{
		temp=num%(-2);
		num/=(-2);
        if(temp < 0)
		{
			num+=1;
			temp+=2;
		}
		printf("%d ",temp);
	}
	puts("");
	}

	return 0;
}

Any Base Conversion

C++ implementation of Any Base to Any Base Conversion.

#include <cstdio>
#include <vector>
#include <iostream>
#include <string>
#include <algorithm>
using namespace std;

#define all(x) x.begin(),x.end()

template<class t> inline t power(t num,t p)
{
    if(!p)    return 1;return (num*power(num,p-1));
}

bool islow(char ch){if(ch>='a' && ch<='z') return true; return false;}
bool isupp(char ch){if(ch>='A' && ch<='Z') return true; return false;}
bool isdig(char ch){if(ch>='0' && ch<='9') return true; return false;}

//any base to decimal conversion
int todec(string s,int base)
{
    int i,j,temp,len,sum=0;

    len=s.length()-1;
    for(i=0,j=len;i<=len;i++,j--)
    {
        char ch=s.at(i);
        if(isdig(ch))         temp=ch-'0';
        else if(islow(ch))    temp=10+ch-'a';
        else if(isupp(ch))    temp=10+ch-'A';

        sum+=(temp*(power(base,j)));
    }

    return sum;
}


//decimal to any base conversion
string tobase(int num,int base)
{
    int temp;
    string s;
    char ch;
    if(!num)    return "0"; //special '0' case handling

    while(num>0)
    {
        temp=num%base;
        num/=base;
        if(temp<=9) s+=(temp+'0');
        else        s+=((temp-10)+'A');
    }
    reverse(all(s));
    return s;
}

Binary to Decimal and Decimal to Binary conversion

Here is a short code for Binary to Decimal Conversion-

int to_dec(string str)
{
    int num=0,i;
    int mask=1;

    for(i=str.length()-1;i>=0;i--)
    {
        if(str.at(i)=='1')
            num|=mask;
        mask<<=1;
    }

        cout << num << endl;
    
    return num;
}

And a short code for Decimal to Binary Conversion-

string to_bin(int num)
{
    string str="";
    int mask=1;

    while(num)
    {
        if(num&mask)
            str="1"+str;
        else
            str="0"+str;

        num>>=1;
    }

    cout << str << endl;
    return str;
}