avoid any switches, better performance

1 files changed, 8 insertions, 25 deletions

diff --git a/count_nucleobases.c b/count_nucleobases.c
index 0396ea6..d1a4f1c 100755
--- a/count_nucleobases.c
+++ b/count_nucleobases.c
@@ -5,10 +5,6 @@
 #include <stdint.h>
 int main(int argc, char **argv) {
 
-  long unsigned long a = 0;
-  long unsigned long c = 0;
-  long unsigned long g = 0;
-  long unsigned long t = 0;
 
   if(argc != 2) {
     printf("Please supply a filename, and only a filename\n");
@@ -21,33 +17,20 @@ int main(int argc, char **argv) {
   }
 
   char line[8192];
+  long unsigned long counts[256];
   while (fgets(line, 8192, fh) != NULL) {
 
-    int i = 0;
-
+    unsigned int i = 0;
     for(i = 0; i < strlen(line); i++) {
-      switch(line[i]) {
-        case 'A':
-        case 'a':
-          a++;
-          break;
-        case 'C':
-        case 'c':
-          c++;
-          break;
-        case 'G':
-        case 'g':
-          g++;
-          break;
-        case 'T':
-        case 't':
-          t++;
-          break;
-      } 
+     counts[line[i]]++;
     }
   }
 
-  printf("A:%llu\nC:%llu\nG:%llu\nT:%llu\n", a, c, g, t);
+  printf("A:%llu\nC:%llu\nG:%llu\nT:%llu\n",
+         counts['a'] + counts['A'],
+         counts['c'] + counts['C'],
+         counts['g'] + counts['G'],
+         counts['t'] + counts['T']);
 
   return EXIT_SUCCESS;
 }