initial commit

teams.c

@@ -0,0 +1,169 @@
+#include <math.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+typedef struct Person {
+  char *name;
+  struct Person *opponent;
+} Person;
+
+static void
+die(const char *fmt, ...)
+{
+  va_list ap;
+
+  va_start(ap, fmt);
+  vfprintf(stderr, fmt, ap);
+  va_end(ap);
+
+  if (fmt[0] && fmt[strlen(fmt)-1] == ':') {
+    fputc(' ', stderr);
+    perror(NULL);
+  } else
+    fputc('\n', stderr);
+  exit(1);
+}
+
+/**
+ * @brief get number of substr in str
+ *
+ * @param haystack str to search
+ * @param needle substr
+ * @return number of substr in str
+ */
+static inline int
+numsubstr(const char *haystack, const char *needle)
+{
+  int i = 0;
+  const char *tmp = haystack;
+
+  while((tmp = strstr(tmp, needle))) {
+    i++;
+    tmp++;
+  }
+
+  return i;
+}
+
+/**
+ * @brief cleanup people ptrs
+ *
+ * @param p pointer to person
+ * @param len number of people in p
+ */
+void
+destroypeopleptr(Person *p, size_t num)
+{
+  int i;
+
+  for (i = 0; i < num; i++)
+    if (p[i].name && p[i].name == NULL)
+      free(p[i].name);
+  free(p);
+}
+
+int
+main(int argc, char *argv[])
+{
+  int j, i, l, t, c, a, r, min, numteams, numpeople, peopleperteam;
+  Person *people, **teams;
+
+  /* seed random number generator */
+  srand(time(NULL));
+
+  /* get number of people declared and allocate enough space for them */
+  for (i = numpeople = 0; i < argc; i++)
+    numpeople += numsubstr(argv[i], "-p");
+
+  /* allocate space for all people */
+  people = calloc(numpeople, sizeof(Person));
+
+  /* collect people and team numbers */
+  i = 0;
+  while ((c = getopt(argc, argv, "p:t:")) != -1) {
+    switch (c) {
+      case 'p':
+        people[i++] = (Person){
+          .name = optarg,
+          .opponent = NULL
+        };
+        break;
+      case 't':
+          numteams = atoi(optarg);
+        break;
+    }
+  }
+
+  /* exit if there aren't enough people for the number of teams */
+  if (floor((double)numpeople / (double)numteams) < 1)
+    die("%d people is not enough for %d teams", numpeople, numteams);
+
+  /* allocate space for teams */
+  teams = calloc(numteams, sizeof(Person *));
+
+  /* calculate maximum number of people per team */
+  peopleperteam = floor(((double)numpeople / (double)numteams) + 0.5);
+
+  /* allocate space for people in each team */
+  for (i = 0; i < numteams; i++)
+    teams[i] = calloc(peopleperteam, sizeof(Person));
+
+  /* randomize array */
+  for (i = 0; i < numpeople; i++) {
+    r = rand() / (RAND_MAX / numpeople);
+    Person tmp = people[r];
+    people[r] = people[i];
+    people[i] = tmp;
+  }
+
+  /* sort people into teams */
+  for (i = j = l = min = 0; i < numpeople; i++) {
+    if (l == peopleperteam) {
+      if (j < numteams - 1) {
+        j++;
+        l = min;
+      } else {
+        /* resize arrays */
+        for (t = 0; t < numteams; t++) {
+          Person *b = calloc(peopleperteam + 1, sizeof(Person));
+
+          for (a = 0; a < peopleperteam; a++) {
+            b[a].name = teams[t][a].name;
+            b[a].opponent = teams[t][a].opponent;
+          }
+
+          destroypeopleptr(teams[t], numpeople);
+          teams[t] = b;
+          b = NULL;
+        }
+
+        j = 0;
+        l = min = peopleperteam++;
+      }
+    }
+
+    /* assign person to team */
+    teams[j][l++] = people[i];
+  }
+
+  /* print out teams */
+  for (i = 0; i < numteams; i++) {
+    printf("team #%d:\n", i + 1);
+    for (j = 0; j < peopleperteam; j++)
+      if (teams[i][j].name)
+        puts(teams[i][j].name);
+  }
+
+  /* cleanup */
+  destroypeopleptr(people, numpeople);
+
+  for (i = 0; i < numteams; i++)
+    free(teams[i]);
+  free(teams);
+
+  return 0;
+}