This snippet can be used to convert from bases between 2 & 16 to base between 2 & 16.

This is an extension on converting decimal to any base snippet found here: http://www.daniweb.com/code/snippet1067.html

(By no means is this the best method of doing this, but provides rather a nice way)

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``````#include <iostream>
#include <string>

std::string conv(std::string number, int startBase, int endbase);
long long power(int num, int pow);

int main(void){
std::string binary = "11010010";
std::cout << "Start Base: Binary (" << binary << ")" << std::endl;
std::cout << "Octal:\t\t" << conv(binary, 2, 8) << std::endl;
std::cout << "Decimal:\t" << conv(binary, 2, 10) << std::endl;
std::cout << "Hexadecimal:\t" << conv(binary, 2, 16) << std::endl << std::endl;

std::string octal = "81";
std::cout << "Start Base: Octal (" << octal << ")" << std::endl;
std::cout << "Binary:\t\t" << conv(octal, 8, 2) << std::endl;
std::cout << "Decimal:\t" << conv(octal, 8, 10) << std::endl;
std::cout << "Hexadecimal:\t" << conv(octal, 8, 16) << std::endl << std::endl;

std::string decimal = "41";
std::cout << "Start Base: Decimal (" << decimal << ")" << std::endl;
std::cout << "Binary:\t\t" << conv(decimal, 10, 2) << std::endl;
std::cout << "Octal:\t\t" << conv(decimal, 10, 8) << std::endl;
std::cout << "Hexadecimal:\t" << conv(decimal, 10, 16) << std::endl << std::endl;

std::string hexadecimal = "A9";
std::cout << "Start Base: Hexadecimal (" << hexadecimal << ")" << std::endl;
std::cout << "Binary:\t\t" << conv(hexadecimal, 16, 2) << std::endl;
std::cout << "Octal:\t\t" << conv(hexadecimal, 16, 8) << std::endl;
std::cout << "Decimal:\t" << conv(hexadecimal, 16, 10) << std::endl << std::endl;
return 0;
}

std::string conv(std::string number, int startBase, int endBase){
if(startBase > 16 || endBase > 16) return "BASE ERROR";
char NUMS[] = "0123456789ABCDEF";
std::string result = "";
int temp = 0, x;
bool found = false;
for(int i = 0; i < number.length(); i++){
for(x = 0; x < startBase; x++){
if(NUMS[x] == number[number.length()-(i+1)]){
found = true;
break;
}
}
if(!found) return "NUMBER ERROR";
temp += (x*power(startBase, i));
}
do{
result.push_back(NUMS[temp%endBase]);
temp /= endBase;
}while(temp != 0);
return std::string(result.rbegin(), result.rend());
}

long long power(int num, int pow){
if(pow == 0) return 1;
return num*power(num, pow-1);
}``````