CS50 Problem Set 1

[Chasca]

Hey guys, I've been following the CS50 lectures online to help teach me C. I'm understanding most of it so far but I'm very stuck on a small part of problem set 1. It involves displaying a variable in the form of currency. I've had a look around via google and have some ideas about what I can do. It's currently a long long variable, and I was thinking of converting it to a string with the format {0;C} but its either not possible or I'm really struggling with the code. Can someone please realign my thinking on the right track? Or any help at all would be great!!!
A brief snippet of my code:

Code: Select all

            printf("Now please input the number of pennies you receive: ");
            float p = GetFloat();
            if(p > 0)
                {
                p = (p/100);   
                long long r = p * pow(2,m);
                printf("For %d days with a start of $%.2f, the total is $%lld!\n",m, p, r);
                ans2 = false;
                ans1 = false;
                }


Currently the long long r is displayed in %lld format. I ideally need to add comma thousand spacing and 2 decimals after.
Again any help would be appreciated. Thanks!

[ghost107]

You could try to transform the 64 bit integer(long long type), into an array of chars, then add ','(comma).

Code: Select all

sprintf(buffer,"%.2lld",my_64bit_integer);
//process your string


[centip3de]

Hey guys, I've been following the CS50 lectures online to help teach me C. I'm understanding most of it so far but I'm very stuck on a small part of problem set 1. It involves displaying a variable in the form of currency. I've had a look around via google and have some ideas about what I can do. It's currently a long long variable, and I was thinking of converting it to a string with the format {0;C} but its either not possible or I'm really struggling with the code. Can someone please realign my thinking on the right track? Or any help at all would be great!!!
A brief snippet of my code:

Code: Select all

            printf("Now please input the number of pennies you receive: ");
            float p = GetFloat();
            if(p > 0)
                {
                p = (p/100);   
                long long r = p * pow(2,m);
                printf("For %d days with a start of $%.2f, the total is $%lld!\n",m, p, r);
                ans2 = false;
                ans1 = false;
                }


Currently the long long r is displayed in %lld format. I ideally need to add comma thousand spacing and 2 decimals after.
Again any help would be appreciated. Thanks!

You've been Googleing, eh? First page Google results for 'Converting a number to a string in C' :
http://www.programmersheaven.com/mb/Can ... functions/
http://www.java2s.com/Code/C/Data-Type/ ... seitoa.htm
http://gcc.gnu.org/ml/gcc-help/2003-12/msg00173.html
http://www.programmersheaven.com/mb/Can ... /?S=B20000
http://www.daniweb.com/software-develop ... -to-string
http://www.ozzu.com/programming-forum/c ... -t266.html
http://www.allegro.cc/forums/thread/588784

I had 10 posted, but the max number of URLs is 7 on HTS.