fix loop

1 files changed, 40 insertions, 13 deletions

diff --git a/brainfuck.c b/brainfuck.c
index ceb52c4..5cd021e 100644
--- a/brainfuck.c
+++ b/brainfuck.c
@@ -8,6 +8,7 @@ typedef struct brainfuck{
         char command[MAX_DATA];
         char *ptr;
         int count;
+        int num;
 }bf;
 
 bf one;
@@ -17,6 +18,7 @@ void init()
         char c;
         memset(&one, 0, sizeof(one));
         one.count = 0;
+        one.num = 0;
         one.ptr = one.data;
 
         while ((c = getchar()) != EOF)
@@ -25,7 +27,7 @@ void init()
                         break;
                 one.command[++one.count] = c;
         }
-        one.command[0] = one.count;
+        one.num = one.count;
         one.command[one.count] = '\0';
 }
 
@@ -33,6 +35,8 @@ void run()
 {
         char c;
         int i;
+        int left;
+        int right;
 
         one.count = 0;
         while (c = one.command[++one.count])
@@ -40,16 +44,22 @@ void run()
                 switch (c)
                 {
                 case '+':
-                        (*one.ptr)++;
+                        if (*one.ptr == 255)
+                                *one.ptr = 0;
+                        else
+                                ++*one.ptr;
                         break;
                 case '-':
-                        (*one.ptr)--;
+                        if (*one.ptr == 0)
+                                *one.ptr = 255;
+                        else
+                                --*one.ptr;
                         break;
                 case '>':
-                        one.ptr++;
+                        ++one.ptr;
                         break;
                 case '<':
-                        one.ptr--;
+                        --one.ptr;
                         break;
                 case ',':
                         *one.ptr = getchar();
@@ -58,31 +68,48 @@ void run()
                         putchar(*one.ptr);
                         break;
                 case '[':
+                        left = 0;
                         if (*one.ptr != 0)
                                 break;
                         else
                         {
-                                for (i = one.count + 1; i <= one.command[0]; i++)
+                                for (i = one.count + 1; i <= one.num; i++)
                                 {
-                                        if (one.command[i] == ']')
+                                        if (one.command[i] == '[')
+                                                ++left;
+                                        else if (one.command[i] == ']')
                                         {
-                                                one.count = i;
-                                                break;
+                                                if (left == 0)
+                                                {
+                                                        one.count = i;
+                                                        break;
+                                                }
+                                                else
+                                                        --left;
                                         }
+                                        
                                 }
                         }
                         break;
                 case ']':
+                        right = 0;
                         if (*one.ptr == 0)
                                 break;
                         else
                         {
                                 for (i = one.count - 1; i >= 1; i--)
                                 {
-                                        if (one.command[i] == '[')
+                                        if (one.command[i] == ']')
+                                                ++right;
+                                        else if (one.command[i] == '[')
                                         {
-                                                one.count = i;
-                                                break;
+                                                if (right == 0)
+                                                {
+                                                        one.count = i;
+                                                        break;
+                                                }
+                                                else
+                                                        --right;
                                         }
                                 }
                         }
@@ -97,4 +124,4 @@ int main(int argc, char **argv)
         init();
         run();
         return 0;
-}
\ No newline at end of file
+}