Left off on exercise 1.23

ch_01/exercise_01-15/main.c

@@ -0,0 +1,32 @@
+/*
+ *
+ * Exercise 1-15. Rewrite the temperature conversion program of Section 1.2 to
+ * use a function for conversion.
+ *
+ * Author: Kun Deng
+ */
+
+#include <stdio.h>
+
+#define UPPER 200
+#define LOWER 0
+#define STEP 10
+
+double convert_to_celsius(double);
+
+int main(int argc, char **argv)
+{
+    printf("%13s %13s\n", "fahrenheit", "celsius");
+
+    for (double fahrenheit = LOWER; fahrenheit <= UPPER; fahrenheit = fahrenheit + STEP)
+    {
+        printf("%13.2f %13.2f\n", fahrenheit, convert_to_celsius(fahrenheit));
+    }
+
+    return 0;
+}
+
+double convert_to_celsius(double fahrenheit)
+{
+    return ((fahrenheit - 32) * 5.0 / 9.0);
+}

ch_01/exercise_01-17/main.c

@@ -0,0 +1,48 @@
+/*
+ *
+ * Exercise 1-17. Write a program to print all input lines that are longer than 80
+ * characters
+ *
+ * Author: Kun Deng
+ */
+
+#include <stdio.h>
+
+#define LINE_LIMIT_COUNT 80
+#define LINE_MAX 1000
+
+int get_line(char line[]);
+
+
+int main(int argc, char **argv)
+{
+    char line[LINE_MAX];
+    int length = 0;
+
+    printf("Enter a sequence of characters.\n");
+    printf("Lines that are greater than %d will be printed to the output\n", LINE_LIMIT_COUNT);
+
+    while(length = get_line(line))
+    {
+        if (length > LINE_LIMIT_COUNT)
+        {
+            printf("%s\n", line);
+        }
+    }
+}
+
+int get_line(char line[])
+{
+    int i = 0;
+    int c;
+
+    for (; ((c = getchar()) != EOF) && c != '\n'; ++i)
+    {
+        line[i] = c;
+    }
+
+    line[i] = '\0';
+
+
+    return i;
+}

ch_01/exercise_01-19/main.c

@@ -0,0 +1,66 @@
+/*
+ *
+ * Exercise 1-19. Write a function reverse(s) that reverses the character string s.
+ * Use it to write a program that reverses its input a line at a time.
+ *
+ * Author: Kun Deng
+ */
+
+#include <stdio.h>
+
+#define UPPER 200
+#define LOWER 0
+#define STEP 10
+#define LINE_MAX_LIMIT 1000
+
+int get_line(char line[]);
+
+void reverse(char whole_string[], int length);
+
+int main(int argc, char **argv)
+{
+    char line[LINE_MAX_LIMIT];
+    int length;
+
+    while ((length = get_line(line)))
+    {
+        printf("before: %s\n", line);
+        reverse(line, length);
+        printf("after: %s\n", line);
+    }
+
+    return 0;
+}
+
+
+
+int get_line(char line[])
+{
+    int i = 0;
+    int c;
+
+    for (; ((c = getchar()) != EOF) && c != '\n'; ++i)
+    {
+        line[i] = c;
+    }
+
+    line[i] = '\0';
+
+
+    return i;
+}
+
+
+void reverse(char whole_string[], int length)
+{
+    int mirrored_index = length - 1;
+
+    for (int i = 0; i != (length / 2); ++i)
+    {
+        char mirrored_char = whole_string[mirrored_index];
+        whole_string[mirrored_index] = whole_string[i];
+        whole_string[i] = mirrored_char;
+
+        --mirrored_index;
+    }
+}

ch_01/exercise_01-20/main.c

@@ -0,0 +1,88 @@
+/*
+ *
+ * Exercise 1-20. Write a program detab that replaces the tabs in the input with the
+ * proper number of blanks to space to the next tab stop. Assume a fixed set of tab
+ * stops, say every n columns. Should n be a variable or a symbolic parameter?
+ *
+ * Author: Kun Deng
+ */
+
+#include <stdio.h>
+
+#define TAB_REPRESENTER 2 // Represents how many spaces a tab would equal
+#define LINE_MAX_LIMIT 1000
+
+char line[LINE_MAX_LIMIT];
+int line_length;
+
+int get_line(void);
+
+void replace_tabs(void);
+
+
+int main()
+{
+    extern int line_length;
+
+    printf("Enter a sequence of characters\n");
+    printf("Any tabs will be replaced with %d white space characters\n", LINE_MAX_LIMIT);
+
+    while (line_length = get_line())
+    {
+        printf("before: %s\n", line);
+        replace_tabs();
+        printf("after: %s\n", line);
+    }
+
+    return 0;
+}
+
+
+int get_line(void)
+{
+    extern char line[];
+    int i = 0;
+    int c;
+
+    for (; (c = getchar()) != EOF && c != '\n'; ++i)
+    {
+        line[i] = c;
+    }
+
+    line[i] = '\0';
+
+    return i;
+}
+
+
+void replace_tabs(void)
+{
+    extern char line[];
+    extern int line_length;
+
+    for (int i = 0; i != line_length; ++i)
+    {
+        char some_char = line[i];
+
+        if (some_char == '\t')
+        {
+            int new_line_length = line_length + TAB_REPRESENTER;
+
+            line[new_line_length] = '\0';
+
+            for (int j = (line_length - 1); j > i; --j)
+            {
+                line[j + TAB_REPRESENTER] = line[j];
+            }
+
+            for (int k = i; k < (i + TAB_REPRESENTER); ++k)
+            {
+                line[k] = ' ';
+            }
+
+            line_length = new_line_length;
+
+            line[i + TAB_REPRESENTER] = 127;
+        }
+    }
+}

ch_01/exercise_01-23/main_template.c

@@ -0,0 +1,6 @@
+/*
+ *
+ * Exercise 
+ *
+ * Author: Kun Deng
+ */

ch_01/main_template.c

@@ -0,0 +1,6 @@
+/*
+ *
+ * Exercise 
+ *
+ * Author: Kun Deng
+ */