diff options
| -rw-r--r-- | 1-13_word-length-histogram.c | 36 | ||||
| -rw-r--r-- | 1-20_detab.c | 5 | ||||
| -rw-r--r-- | 1-21_entab.c | 43 | ||||
| -rw-r--r-- | README.mdown | 22 |
4 files changed, 60 insertions, 46 deletions
diff --git a/1-13_word-length-histogram.c b/1-13_word-length-histogram.c index 1e21378..d3115a5 100644 --- a/1-13_word-length-histogram.c +++ b/1-13_word-length-histogram.c @@ -6,18 +6,17 @@ 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. - */ + * i, j = reusable placeholder variables + * 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 state, ltrs, wrds, lines, wlen, i, j; int lengths[MAXWLENGTH]; - int i; for (i = 0; i <= MAXWLENGTH; ++i) { lengths[i] = 0; } @@ -26,9 +25,9 @@ int main(void) { lines = 1; state = OUT; // Capture input until it ends - while ((c = getchar()) != EOF) { + while ((i = getchar()) != EOF) { // If it's whitespace, we've exited a word - if (c == '\n' || c == ' ' || c == '\t') { + if (i == '\n' || i == ' ' || i == '\t') { if (state == IN) { ++wrds; // ...and should increase the count. state = OUT; @@ -41,7 +40,7 @@ int main(void) { } /* If it's a new line, we're still out of a word but need to increment the line count */ - if (c == '\n') { + if (i == '\n') { ++lines; } } else { @@ -59,19 +58,18 @@ int main(void) { } printf("\n"); // End the chart heading. - int iter; - iter = MINWLENGTH; - while (iter <= MAXWLENGTH) { - i = lengths[iter]; + j = MINWLENGTH; + while (j <= MAXWLENGTH) { + i = lengths[j]; if (i > 0) { - printf("%2d | ", iter); + printf("%2d | ", j); while (i > 0) { printf("#"); i = i-1; } printf("\n"); } - ++iter; + ++j; } printf("%d words, %d chars, %d lines.\n", wrds, ltrs, lines); return 0; diff --git a/1-20_detab.c b/1-20_detab.c index e1549e6..dc8f5b5 100644 --- a/1-20_detab.c +++ b/1-20_detab.c @@ -11,9 +11,8 @@ * worked with and it's not susceptible to scope. Though, in this simple * program it really doesn't matter. * - * To be correct, this file should use the isprint() function to ensure that - * 'column' only gets incremented when a printable character is being read. I'll - * come back to this when I learn more of the stdlib. + * The "correct" solution uses the isprint() stdlib function, but it's not + * covered by this point in the book, so I did not use it. */ #define TABWIDTH 8 diff --git a/1-21_entab.c b/1-21_entab.c index 0f25706..6037a14 100644 --- a/1-21_entab.c +++ b/1-21_entab.c @@ -15,30 +15,41 @@ #define TABWIDTH 8 int main(void) { - int c, spaces; - spaces = 0; + int column, c, spaces; + spaces = column = 0; while ((c = getchar()) != EOF) { - // Make sure the character is a space... + // First thing's first, advance by a column. + column++; + if (c == ' ') { - ++spaces; - // When spaces is equal to TABWIDTH, we can add a tab - if (spaces == TABWIDTH) { + /* Add to 'spaces' immediately, we'll decide if it needs to be + * output later. + */ + spaces++; + + if (column % TABWIDTH == 0 && spaces > 0) { putchar('\t'); - spaces = 0; + spaces = 0; // No spaces are left when we tab! } + } else { - /* As soon as we hit a non-space character, we need to make sure - * there aren't 1-7 spaces leftover. These need to be output before - * we output the non-space character itself! This little loop is - * interesting because it solves the problem of leftover spaces - * _and_ gets the 'spaces' back to zero, which it needs to be once - * we hit a non-space character. + /* Be sure to output any leftover spaces when we come across a + * non-space character. This should allow for spaces between words + * that don't fall along the tabstop lines. */ - while (spaces != 0) { + + while (spaces > 0) { putchar(' '); - --spaces; + spaces--; } - // Output the non-space character. + + // As usual, reset things on a newline. + if (c == '\n') { + column = 0; + spaces = 0; + } + + // Now we can output whatever it is. putchar(c); } } diff --git a/README.mdown b/README.mdown index 7af39e0..1fafb61 100644 --- a/README.mdown +++ b/README.mdown @@ -1,9 +1,15 @@ -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! +These files are my solutions to Kernighan and Ritchie's *The C Programming +Language, 2nd Edition*. My aim is to deepen my understanding of C, using only +the concepts covered in content that comes before each exercise. That means no +"cheating" by using standard library features that aren't been covered in the +book yet. As a result, many of my solutions will probably not be "the best", but +suitable for the goal at hand: *learning*. -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. +I chose this route because as I was reading the K&R, I didn't feel like I was +learning anything new, but I knew C was known for its simplicity and efficiency. +If I wasn't learning anything about efficiency and simplifying my programs, then +why was I learning C? I tackled a few exercises and found that I was beginning +to learn a few things I hadn't ran into before. + +Critique is welcome, but please keep in mind the limitations I've outlined in +the first paragraph. |