C: grade school

c/grade-school/src/grade_school.c

@@ -0,0 +1,84 @@
+#include "grade_school.h"
+#include <string.h>
+#include <stdio.h>
+
+#define STD(i) roster.students[i]
+#define NAME(i) roster.students[i].name
+#define GRADE(i) roster.students[i].grade
+
+static roster_t roster;
+
+void clear_roster()
+{
+    roster.count=0;
+}
+
+/* testing program expects bool here, but I prefer to return students count,
+ * it makes more sense for me.
+ */
+int add_student(char *s, uint8_t g)
+{
+    int c=roster.count;
+    int i;
+
+    if (c >= MAX_STUDENTS)
+        return 0;
+    // find correct place to insert name
+    for (i=0; i<c && (GRADE(i)<g || (GRADE(i)==g && strcmp(s, NAME(i))>0)); ++i)
+        ;
+    for (int j=c-1; j>=i; --j)                    /* move rest to right */
+        STD(j+1)=STD(j);
+    NAME(i)=s;                                    /* insert new name */
+    GRADE(i)=g;
+
+    return ++roster.count;
+}
+
+/* to avoid this everytime, we could build up one roster per grade while
+ * adding students, but really overkill here.
+ */
+roster_t get_grade(uint8_t g)
+{
+    static roster_t r;
+    unsigned i, j=0;
+
+    for (i=0; i<roster.count && GRADE(i)<=g; ++i) {
+        if (GRADE(i)==g)
+            r.students[j++]=STD(i);
+    }
+    r.count=j;
+
+    return r;
+}
+
+roster_t get_roster()
+{
+    return roster;
+}
+
+
+/* See GNUmakefile below for explanation
+ * https://github.com/braoult/exercism/blob/master/c/templates/GNUmakefile
+ */
+#ifdef UNIT_TEST
+static void print_roster()
+{
+    unsigned i;
+    printf("======== roster size: %lu\n", roster.count);
+    for (i=0; i<roster.count; ++i)
+        printf("roster(%02d): [%d]%s\n", i, GRADE(i), NAME(i));
+    printf("\n");
+}
+
+int main(int ac, char **av)
+{
+    int arg=1;
+    uint8_t i;
+
+    for (; arg<ac-1; ++arg, ++arg) {
+        i=atoi(av[arg]);
+        add_student(av[arg+1], i);
+    }
+    print_roster();
+}
+#endif

c/grade-school/src/grade_school.h

@@ -0,0 +1,38 @@
+#ifndef GRADE_SCHOOL_H
+#define GRADE_SCHOOL_H
+
+#include <stddef.h>
+#include <stdint.h>
+//#include <stdbool.h>
+
+#define MAX_NAME_LENGTH 20
+#define MAX_STUDENTS    20
+
+typedef struct student_s {
+    uint8_t grade;
+    char *name;
+} student_t;
+
+typedef struct {
+    size_t count;
+    student_t students[MAX_STUDENTS];
+} roster_t;
+
+void clear_roster();
+int add_student(char *, uint8_t);
+roster_t get_grade(uint8_t);
+roster_t get_roster();
+
+/* See GNUmakefile below for explanation
+ * https://github.com/braoult/exercism/blob/master/c/templates/GNUmakefile
+ */
+#if defined UNIT_TEST || defined DEBUG
+#include <stdio.h>
+#include <stdlib.h>
+#endif
+#ifdef  TESTALL
+#undef  TEST_IGNORE
+#define TEST_IGNORE() {}
+#endif
+
+#endif