1 files changed, 36 insertions, 18 deletions

diff --git a/6.3/main.c b/6.3/main.c
index cd52cec..5c35e24 100644
--- a/6.3/main.c
+++ b/6.3/main.c
@@ -7,25 +7,20 @@
 #define MAXWORD	100
 #define ARR_SIZE(X) (sizeof(X)/sizeof(X[0]))
 
-const char *noise[] = {
-	"the",
-	"and"
-};
-
-int isnoise(char *word);
+int noiseword(char *w);
 
 int main(void)
 {
 	char word[MAXWORD];
 	struct tnode *root;
-	int line = 0;
+	int linenum = 0;
 	
 	root = NULL;
 	while (getword(word, MAXWORD) != EOF)
-		if (isalpha(word[0]) && !isnoise(word))
-			root = addtree(root, word, line);
+		if (isalpha(word[0]) && noiseword(word) == -1)
+			root = addtree(root, word, linenum);
 		else if(word[0] == '\n')
-			++line;
+			++linenum;
 
 	tprint(root);
 	tfree(root);
@@ -33,13 +28,36 @@ int main(void)
 	return 0;
 }
 
-int isnoise(char *word)
+int noiseword(char *w)
 {
-	size_t i;
-
-	for(i = 0; i < ARR_SIZE(noise); ++i)
-		if (!strcmp(word, noise[i]))
-			return 1;
-
-	return 0;
+	const char *noise[] = {
+		"a",
+		"an",
+		"and",
+		"are",
+		"in",
+		"is",
+		"of",
+		"or",
+		"that",
+		"the",
+		"this",
+		"to"
+	};
+
+	int cond, mid;
+	int low = 0;
+	int high = ARR_SIZE(noise);
+
+	while (low < high) {
+		mid = (low + high) / 2;
+		if ((cond = strcmp(w, noise[mid])) < 0)
+			high = mid;
+		else if (cond > 0)
+			low = mid + 1;
+		else
+			return mid;
+	}
+
+	return -1;
 }