Help with pseudocode

[EatMyChidori]

Can someone help me with writing a pseudocode for converting hex to decimal?

[bloodx]

maybe this?

    int x;
    std::cin >> std::hex >> x;
    std::cout << x << std::endl;

    return 0;

[EatMyChidori]

Could you kindly explain what those things even mean? LOL. My class for programming just started and i dont know much

[.SkyneT.]

Originally Posted by EatMyChidori

Could you kindly explain what those things even mean? LOL. My class for programming just started and i dont know much

std::cin >> std::hex >> x;

Saves an hexadecimal value to x.

std::cout << x << std::endl;

or

std::cout << std::dec <<  x << std::endl;

Shows the value in the decimal system.

[MrSm!th]

That's no pseudo code.

[Cowmangler]

Here's some C-inspired "pseudocode"

mul = 1;
for (i = hex.length; i>= 0; i--, mul*16)
{
result += hex[i] * mul;
}

I hope that's what you were looking for

[MrSm!th]

That wouldn't do the job, since hex characters may include letters (A-F) that cannot be multiplied with 16.

[Ensky]

Well, it's bad pseudo-code and only a "quick'n'dirty" solution, but maybe it helps... :-)

long f(character *a, integer length)
{
integer i;
long value = 0;

for(i=0;i<length;i++)
if(a[i] <= 57) //look at ASCII Table, if you don't understand this :-)
value += (a[i]-48) * (1 leftshift (4*(length-1-i)));
else
value += (a[i]-55) * (1 leftshift (4*(length-1-i)));
return value;
}

[Jadd]

C++ solution was posted above, however this is the C solution:

int nInteger = 0;
scanf_s( "%x", &nInteger );
printf_s( "%i", nInteger );

[MrSm!th]

Originally Posted by Jadd

C++ solution was posted above, however this is the C solution:

int nInteger = 0;
scanf_s( "%x", &nInteger );
printf_s( "%i", nInteger );

Well, I'm clearly sure, that he needs to write the algorithm himself instead of using libraries.

[kissein]

Algo works from right to left.

Divide number by 16. Keep the quotient for next iteration, the remainder is the figure you are looking for. It will ovbviously be between 0 and 15, convert that to 0..F
As long as quotient is >= 16, repeat.

[Ensky]

Originally Posted by kissein

Algo works from right to left.

Divide number by 16. Keep the quotient for next iteration, the remainder is the figure you are looking for. It will ovbviously be between 0 and 15, convert that to 0..F
As long as quotient is >= 16, repeat.

he want's to convert hex to decimal, not decimal to hex :-)

[kissein]

Originally Posted by Ensky

he want's to convert hex to decimal, not decimal to hex :-)

ups sorry, my fault.

-Get the last digit of the hex number, call this digit the currentDigit.
-Make a variable, let's call it power. Set the value to 0.
-Multiply the current digit with (16^power), store the result.
-Increment power by 1.
-Set the the currentDigit to the previous digit of the hex number.
-Repeat from step 3 until all digits have been multiplied.
-Sum the result of step 3 to get the answer number.

Example:

Convert the number 35432 HEXADECIMAL to DECIMAL

2x(16^0) + 3x(16^1) + 4x(16^2) + 5x(16^3) + 3x(16^4) =
2 + 3x16 + 4*256 + 5*4096 + 3*65536 =
2 + 48 + 1024 + 20480 + 196608 =
218162