From 569a5bd5c48d8969e644947ce3d89a97a0d56e5e Mon Sep 17 00:00:00 2001 From: zlg Date: Sat, 11 Aug 2012 14:55:41 -0400 Subject: Initial commit --- .gitignore | 6 ++++ 1-13_word-length-histogram.c | 73 +++++++++++++++++++++++++++++++++++++++++ 1-14_character-freq-histogram.c | 51 ++++++++++++++++++++++++++++ 1-15_temp-convert-func.c | 18 ++++++++++ 1-16_longest-line.c | 52 +++++++++++++++++++++++++++++ 1-17_over-80.c | 62 ++++++++++++++++++++++++++++++++++ README.mdown | 9 +++++ 7 files changed, 271 insertions(+) create mode 100644 .gitignore create mode 100644 1-13_word-length-histogram.c create mode 100644 1-14_character-freq-histogram.c create mode 100644 1-15_temp-convert-func.c create mode 100644 1-16_longest-line.c create mode 100644 1-17_over-80.c create mode 100644 README.mdown diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..67f42e5 --- /dev/null +++ b/.gitignore @@ -0,0 +1,6 @@ +* + +!*.c +!*.h +!.gitignore +!README.mdown diff --git a/1-13_word-length-histogram.c b/1-13_word-length-histogram.c new file mode 100644 index 0000000..1b4cdc0 --- /dev/null +++ b/1-13_word-length-histogram.c @@ -0,0 +1,73 @@ +#include +#define IN 1 +#define OUT 0 +#define MINWLENGTH 2 +#define MAXWLENGTH 20 + +int main(void) { + /* Rundown of variables: + c = current input char + state = inside or outside a word + ltrs = letter count + wrds = word count + lines = you should be shot if you don't know + lengths = an array that keeps track of how often words up to x chars long + occur. + */ + + int c, state, ltrs, wrds, lines, wlen; + int lengths[MAXWLENGTH]; + int i; + for (i = 0; i <= MAXWLENGTH; ++i) { + lengths[i] = 0; + } + + ltrs = wrds = wlen = 0; + lines = 1; + state = OUT; + // Capture input until it ends + while ((c = getchar()) != EOF) { + // If it's whitespace, we've exited a word + if (c == '\n' || c == ' ' || c == '\t') { + if (state == IN) { + ++wrds; // ...and should increase the count. + state = OUT; + /* Check to see if the word is eligible to be counted. */ + if (wlen <= MAXWLENGTH) { + ++lengths[wlen]; + } + // Reset our word length now. + wlen = 0; + } + /* If it's a new line, we're still out of a word but need to increment the + line count */ + if (c == '\n') { + ++lines; + } + } else { + /* If nothing else, we know it's just a random character or a letter. */ + state = IN; + ++wlen; + } + /* Everything that's input counts as a letter. */ + ++ltrs; + } + // This is ugly and I wish I knew a better way to do it. + printf("\nWORD LENGTH FREQUENCY\n\n 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75\n"); + int iter; + iter = MINWLENGTH; + while (iter <= MAXWLENGTH) { + i = lengths[iter]; + if (i > 0) { + printf("%2d | ", iter); + while (i > 0) { + printf("#"); + i = i-1; + } + printf("\n"); + } + ++iter; + } + printf("%d words, %d chars, %d lines.\n", wrds, ltrs, lines); + return 0; +} diff --git a/1-14_character-freq-histogram.c b/1-14_character-freq-histogram.c new file mode 100644 index 0000000..14c4871 --- /dev/null +++ b/1-14_character-freq-histogram.c @@ -0,0 +1,51 @@ +#include +int main(void) { + /* Rundown of variables: + c = current input char + ltrs = letter count + chars = string containing the characters the program will count + lengths = the counts for each character + */ + + int c; + int i = 0; + char chars[] = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"; + + /* cnum is the number of characters found in the above string */ + int cnum = 0; + while (chars[i] != '\0') { + cnum += 1; + ++i; + } + + /* This array need its members to be initialized to zero. */ + int lengths[cnum]; + for (i = 0; i <= cnum; ++i) { + lengths[i] = 0; + } + + // Capture input until it ends + while ((c = getchar()) != EOF) { + for (i = 0; i < cnum; ++i) { + if (c == chars[i]) { + lengths[i] += 1; + } + } + } + // This is ugly and I wish I knew a better way to do it. + printf("\nCHARACTER FREQUENCY\n\n 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75\n"); + int iter = 0; + while (iter <= cnum) { + i = lengths[iter]; + if (i > 0) { + printf("%2c | ", chars[iter]); + while (i > 0) { + printf("#"); + i -= 1; + } + printf("\n"); + } + ++iter; + } + return 0; +} diff --git a/1-15_temp-convert-func.c b/1-15_temp-convert-func.c new file mode 100644 index 0000000..aa59cf6 --- /dev/null +++ b/1-15_temp-convert-func.c @@ -0,0 +1,18 @@ +#include + +#define MAX_F 300.0 +#define STEP 20.0 + +float convert_to_c(float f) { + float celsius = (5.0 / 9.0) * (f - 32.0); + return celsius; +} + +int main() { + printf("FAHRENHEIT CELSIUS\n"); + float i; + for (i = 0.0; i <= MAX_F; i += STEP) { + printf("%4.0f %7.3f\n", i, convert_to_c(i)); + } + return 0; +} diff --git a/1-16_longest-line.c b/1-16_longest-line.c new file mode 100644 index 0000000..1f6e556 --- /dev/null +++ b/1-16_longest-line.c @@ -0,0 +1,52 @@ +#include + +#define MAXLENGTH 100 + +int get_line(char s[], int lim) { + /* Put as much as possible into a temp string, and count its length */ + int c, i; + + for (i = 0; i < lim && (c = getchar()) != EOF && c != '\n'; ++i) { + s[i] = c; + } + if (c == '\n') { + s[i] = c; + ++i; + } + s[i] = '\0'; + return i; +} + +void copy(char from[], char to[]) { + int i = 0; + + while ((to[i] = from[i]) != '\0') { + ++i; + } +} + +int main() { + int len, max; + + char line[MAXLENGTH]; + char longest[MAXLENGTH]; + + max = 0; + while ((len = get_line(line, MAXLENGTH)) > 0) { + if (len > max) { + max = len; + copy(line, longest); + } + } + + printf("\nThe longest line is %3d characters long.\n", max); + printf("----------------------------------------\n"); + if (max > 0) { + printf("%-s", longest); + if (max == MAXLENGTH && longest[max - 1] != '\n') { + printf("\n"); + } + } + + return 0; +} diff --git a/1-17_over-80.c b/1-17_over-80.c new file mode 100644 index 0000000..dcf7058 --- /dev/null +++ b/1-17_over-80.c @@ -0,0 +1,62 @@ +#include + +#define MINLENGTH 80 + +/* Read as much as possible of a string and return its length. */ +int get_line(char s[]) { + int c, i; + + for (i = 0; i < MINLENGTH - 1 && (c = getchar()) != EOF; ++i) { + s[i] = c; + } + if (c == '\n') { + s[i] = c; + ++i; + } + s[i] = '\0'; + return i; +} + +int main() { + // longline is used as a boolean that tells us if it's a line worth printing + int longline = 0; + + // len is simply a character counter, while c is the character itself. + int len, c; + char buffer[MINLENGTH]; + + while ((c = getchar()) != EOF) { + buffer[len] = c; + + /* When we meet the end of the line, we need to print the rest of the line, + but only if we're already in a long line. Otherwise, reset our state. + */ + if (c == '\n') { + + if (longline == 1 && len < MINLENGTH - 1) { + buffer[len + 1] = '\0'; + printf("%-s", buffer); + } + + len = 0; + longline = 0; + continue; + } + + /* When the buffer has filled up, output its contents! */ + if (len == MINLENGTH) { + buffer[len + 1] = '\0'; + printf("%-s", buffer); + len = 0; + longline = 1; + continue; + } + + /* If neither of the above cases are caught, increment our counter and fetch + more data. + */ + ++len; + } + + return 0; +} diff --git a/README.mdown b/README.mdown new file mode 100644 index 0000000..7af39e0 --- /dev/null +++ b/README.mdown @@ -0,0 +1,9 @@ +As I was reading Kernighan and Ritchie's *The C Programming Language*, I felt +like I was learning the syntax and other superficial things, but not learning +the more practical lessons that I was sure I'd run into once I tried to make +something. So I chose to do the exercises. I didn't start until the middle of +Chapter 1, but better late than never! + +If you have suggestions or pointers, message me! I really want to learn C "the +right way". It's a fascinating, spartan, pretty language, and I want to become +good with it. -- cgit v1.2.3-54-g00ecf