September 2011

There were 18 posts published in September 2011 (this is page 4 of 5).

The C Programming Language (TCPL): Chapter 6

Exercise 6-4. Write a program that prints a distinct words in its input sorted into decreasing order of frequency of occurrence. Precede each word by its count.

#include
#include
#include

#define MAXWORDS 1024
#define MAXLENGTH 512

struct word {
char *name;
int count;
};

struct word wordlist[MAXWORDS];
int wordn = 0;

/* prototypes */
char *allocword(char *str);
int isword(char *str);
void addword(char *str);
int wordcmp(const void *a, const void *b);
void printwords();

int main()
{

char inputbuff[MAXLENGTH];
char tmpbuff[MAXLENGTH];
char *tmp;

while(fgets(inputbuff, MAXLENGTH, stdin) != NULL)
{

int i, k;
for(i = 0; inputbuff[i] != ''; i++)
{
if((inputbuff[i] == ' ' || inputbuff[i] == 't' || inputbuff[i] == 'n') && k != 0)
{
tmp = allocword(tmpbuff);
if(tmp == NULL)
{
printf("Error: Can't allocate enough space.n");
return 1;
}
strlcpy(tmp, tmpbuff, strlen(tmpbuff) + 1);
addword(tmp);
k = 0;
}
else
{
tmpbuff[k++] = inputbuff[i];
tmpbuff[k] = '';
}
}
}

printwords();
return 0;
}

char *allocword(char *str)
{
return (char *)malloc(sizeof(char) * (strlen(str) + 1));
}

int isword(char *str)
{
int i;
for(i = 0; i < wordn; i++) { if(!strncmp(wordlist[i].name, str, strlen(str))) { return i; } } return -1; } void addword(char *str) { int index; if((index = isword(str)) >= 0)
{
wordlist[index].count += 1;
} else {
wordlist[wordn].name = str;
wordlist[wordn].count = 1;
wordn++;
}

}

int wordcmp(const void *a, const void *b)
{
struct word *fst = (struct word *)a;
struct word *snd = (struct word *)b;

return -(fst->count - snd->count);
}

void printwords()
{
int i;

qsort(wordlist, wordn, sizeof(struct word), wordcmp);
for(i = 0; i < wordn; i++) { printf("%3i | %sn", wordlist[i].count, wordlist[i].name); } }

The C Programming Language (TCPL): Chapter 5

Exercise 5-10. Write a program expr, which evalutes a reverse Polish expression from the command line, where each operator or operand is a separate argument. For example, expr 2 3 4 + * evalutes 2 x (3 + 4).

#include
#include
#include

#define STACKSIZE 1024

double stack[STACKSIZE];
int stackn = 0;

double pop()
{
return stack[--stackn];
}

void push(double x)
{
stack[stackn++] = x;
}

int main(int argc, char *argv[])
{
int i;
double value = 0;

for(i = 1; i < argc; i++) { push(atof(argv[i])); float tmp; if(strlen(argv[i]) < 2) { if(argv[i][0] == '+') { pop(); /* removes operator */ push(pop() + pop()); } if(argv[i][0] == '-') { pop(); tmp = pop(); push(pop() - tmp); } if(argv[i][0] == '*') { pop(); push(pop() * pop()); } if(argv[i][0] == '/') { pop(); tmp = pop(); if (tmp != 0.0) { push(pop() / tmp); } else { printf("DIV BY 0n"); return 1; } } } } printf("%.2fn", pop()); return 0; }

The C Programming Language (TCPL): Chapter 4

Exercise 4-13. Write a recursive version of the function reverse(s), which reverses the string s in place.

#include
#include

void switchchar(char s[], int i, int j)
{
char tmp;

tmp = s[i];
s[i] = s[j];
s[j] = tmp;
}

void reverse(char s[])
{
static int i = 0;
static int len = 0;

if(i == 0)
{
len = strlen(s) - 1;
}

switchchar(s, i, (len - i));

i++;
if(i <= (len / 2)) { reverse(s); } } int main() { char str[] = "ABCDEF123456"; reverse(str); printf("%sn", str); return 0; }

#82/111: Confessions Of An Advertising Man

What is it about?

If you are interested in advertising you probably heard of David Ogilvy. He’s the master mind behind one of the greatest advertisements of the last century. In this book he talks about his work ethics, marketing research and how he ran his company.

What can I learn?

You can’t bore someone into buying: Although Ogilvy was one of the more conservative advertisers he knew that you need an interesting idea behind your ad. Your prospects should be energized by reading/watching your ad. You can’t sell them something, if they won’t buy it.

Promote hard work: Ogilvy discovered early that the corporate culture is essential for great work. He wanted a culture affected by hard work and not by politics. He said: “We admire people who work hard, who are objective and thorough. We detest office politicians, toadies, bullies and pompous asses. We abhor ruthlessness. The way up our ladder is open to everybody. In promoting people to top jobs, we are influenced as much by their character as anything else.”

Research is important: Claude Hopkins was one of Ogilvy’s role models. He preached that you should eliminate the guessing process and work with testing and research. Ogilvy, who worked as a researcher at Gallup, never forgot this mantra.

Conclusion

Confessions Of An Advertising Man is a truly great book. Ogilvy is famous for his superb writing skills and it’s a pleasure to read this book. If you want to work in advertising you should read this book as soon as possible. Even for non-ad people this should be an interesting lecture.