Add letter pool specification and readme

Makefile

@@ -1,4 +1,11 @@
-GCC = gcc -O2
+GCC = gcc -O3 --static
 
 default: main.c
 	$(GCC) main.c -o banagram
+
+install: default
+	cp banagram /usr/bin/banagram
+
+uninstall:
+	rm /usr/bin/banagram
+

README.md

@@ -0,0 +1,23 @@
+# Banagram.c
+
+An anagram finder optimised for the game bananagrams-battle. It allows finding 
+words that contain all the letters of a given word, plus any given number of 
+letters from a pool of available letters. 
+
+To do this use 
+
+```
+$ banagram min <num extra letters> <word> <(optional) string of available letters>"
+```
+
+Alternatively, to find all words containing exactly all the same letters as a 
+given word, use:
+
+```
+$ banagram exact word
+```
+
+## TODO:
+
+- Improve interface, replace manual parsing code with `getopt(3)`
+- General cleanup and commenting

main.c

@@ -2,9 +2,10 @@
 #include <string.h>
 #include <stdlib.h>
 #include <ctype.h>
+#include <stdbool.h>
 
 /*
- * Copyright 2020 Alistair 
+ * Copyright 2020 Alistair Michael
  * 
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the
@@ -27,13 +28,13 @@
  *
  */
 
+#define LINELENGTH 200
+
 // for string qsort
 int compar(const void * l1, const void *l2) {
     return *(char *)l1 > *(char*)l2;
 }
 
-#define LINELENGTH 200
-
 void make_lowercase(char *word) {
     int j = 0;
     while (word[j] != '\0') {
@@ -46,7 +47,7 @@ void make_lowercase(char *word) {
 
 int *count_char(char *word) {
     make_lowercase(word);
-    int* counts = calloc(27, sizeof(int));
+    int* counts = (int*)calloc(27, sizeof(int));
 
     int j = 0;
     while (word[j] != '\0') {
@@ -59,8 +60,9 @@ int *count_char(char *word) {
     }
     return counts;
 }
-
-int get_minimum_match(char *word, int added) {
+// @param allowed: additional characters allowed in anagram match, 
+// set to NULL to allow matching any set of characters.
+int get_minimum_match(char *word, int added, char *allowed) {
     FILE *wfile = fopen("words", "r");
     char line[LINELENGTH];
     int err;
@@ -87,11 +89,25 @@ int get_minimum_match(char *word, int added) {
             continue;
         }
 
-        int match = 1;
+        bool match = true;
 
         for (int i = 0; i < 26; i++) {
             if (min_letter_counts[i] > word_counts[i]) {
-                match = 0;
+                match = false;
+                break;
+            }
+
+            if (allowed && word_counts[i] > 0) {
+                bool in = false;
+                for (int j = 0; allowed[j] != '\0'; j++) {
+                    if (allowed[j] == (i + 'a')) 
+                        in = true;
+                }
+
+                if (!in) {
+                    match = false;
+                    break;
+                } 
             }
         }
 
@@ -151,11 +167,14 @@ int get_exact_anag(char *word) {
 }
 
 int main (int argc, char **argv) {
+    char *usage_string = "cmd min <num extra letters> <word> <(optional) pool "
+        "of available letters>"
+        "\ncmd exact <word>\n";
     
     char word[LINELENGTH];
 
     if (argc <= 2) {
-        printf("cmd min <num extra letters> <word>\ncmd exact <word>\n");
+        fprintf(stderr, "%s", usage_string);
         return 1;
     }
 
@@ -167,7 +186,7 @@ int main (int argc, char **argv) {
         strcpy(word, argv[2]);
         get_exact_anag(word);
     } else if (argv[1][0] == 'm') {
-        if (argc != 4) {
+        if (argc < 4 || argc > 5) {
             fprintf(stderr, "Wrong args.\n");
             return 1;
         }
@@ -176,9 +195,12 @@ int main (int argc, char **argv) {
         if (num == 0) {
             get_exact_anag(word);
         } else {
-            get_minimum_match(word, num);
+            char *allowed = NULL;
+            if (argc == 5) 
+                allowed = argv[4];
+            get_minimum_match(word, num, allowed);
         }
     } else {
-        printf("cmd min <num extra letters> <word>\ncmd exact <word>\n");
+        fprintf(stderr, "%s", usage_string);
     }
 }