Almost complete

Need to account for the -f flag

ch_05/exercise_05-15/main.c

@@ -5,12 +5,140 @@ distinctions are not made during sorting; for example, a and A compare equal.
  *
  * Author: Kun Deng
  */
+#include <stdio.h>
+#include <string.h>
+
+#define MAXLINES 5
+char *lineptr[MAXLINES];
 
 
-main(int argc, char **argv)
+void qsort(void *v[], int left, int right, int (*comp)(void *, void *));
+void swap(void *[], int i, int j);
+int numcmp(char *s1, char *s2);
+int strcmp_ignore(char *s1, char *s2);
+
+int readlines(char *lptr[], int nlines);
+void writelines(char *lptr[], int nlines);
+
+
+void qsort(void *v[], int left, int right, int (*comp)(void *, void *)) {
+    int i, last;
+
+    if (left >= right)
+        return;
+
+    swap(v, left, (left + right)/2);
+    last = left;
+    for (i = left+1; i <= right; i++) {        
+        if ((*comp)(v[i], v[left]) < 0)
+            swap(v, ++last, i);
+    }
+
+    swap(v, left, last);
+    qsort(v, left, last-1, comp);
+    qsort(v, last+1, right, comp);
+}
+
+void swap(void *v[], int i, int j) {
+    void *tmp;
+
+    tmp = v[i];
+    v[i] = v[j];
+    v[j] = tmp;
+}
+
+int numcmp(char *s1, char *s2) {
+    double v1, v2;
+
+    v1 = atof(s1);
+    v2 = atof(s2);
+
+    if (v1 < v2)
+        return -1;
+    else if (v1 > v2)
+        return 1;
+    else
+        return 0;
+}
+
+// TODO: Implement function
+int strcmp_ignore(char *s1, char *s2) {
+    return 0;
+}
+
+int readlines(char *lptr[], int nlines) {
+    int i = 0;
+
+    printf("Enter some lines\n");
+
+    int max = 25;
+
+    for (; i < nlines; i++) {
+        char line[max];
+        char c = getchar();
+        int ii = 0;
+
+        while (c != EOF) {
+            line[ii++] = c;
+            c = getchar();
+        }
+
+        lptr[i] = line;
+    }
+
+    return i;
+}
+
+void writelines(char *lptr[], int nlines)
 {
-    auto i = 0;
+    for (int i = 0; i < nlines; i++) {
+        printf("%s\n", lptr[i]);
+    }
+}
 
+int testlines(char *lineptr[]) {
+    lineptr[0] = "ffffc";
+    lineptr[1] = "zzzz";
+    lineptr[2] = "aaaa";
+    lineptr[3] = "bbsss";
+    lineptr[4] = "osp";
+
+    return 5;
+}
+
+
+int main(int argc, char **argv)
+{
+    int nlines;
+    int numeric = 0;
+
+    if (argc > 1 && strcmp(argv[1], "-n") == 0)
+        numeric = 1;
+    else if (argc > 1 && strcmp(argv[1], "-f") == 0)
+        numeric = 3;
+
+    if ((nlines = testlines(lineptr)) >= 0 ) {
+        printf("Currently\n");
+        writelines(lineptr, nlines);
+
+        if (numeric != 3) {
+            void (*my_func) = (numeric ? numcmp : strcmp);
+
+            qsort((void **) lineptr, 0, nlines-1, 
+                (int (*)(void *, void *))my_func);
+        } else {
+            void (*my_func) = strcmp_ignore;
+            qsort((void **) lineptr, 0, nlines-1, my_func);
+                
+        }
+
+        printf("\nAfter\n");
+        writelines(lineptr, nlines);
+        return 0;
+    } else {
+        printf("Input too big to sort\n");
+        return 1;
+    }
 
     return 0;
 }