Implement double arithmetic with error bounds.

1 files changed, 5 insertions, 1 deletions

diff --git a/ratio.c b/ratio.c
index 8f86f93..384f944 100644
--- a/ratio.c
+++ b/ratio.c
@@ -2,6 +2,7 @@
 #include <stdlib.h>
 #include <math.h>
 #include <limits.h>
+#include <float.h>
 
 typedef unsigned long long num;
 
@@ -35,6 +36,8 @@ rational convert_int(int i){
 	return r;
 }
 
+unsigned int to_exptype(unsigned int i){ return i; } 
+
 num gcd(num a, num b){
 	num c;
 	while (b) {
@@ -120,6 +123,7 @@ double to_double(rational r){
 }
 
 bool to_string(char* s,rational r){
-	sprintf(s,"%llu / %llu",r.n,r.d);
+	double f = to_double(r);
+	sprintf(s,"%llu / %llu = %f +- %.24f",r.n,r.d,f,f*DBL_EPSILON);
 	return true;
 }