1 #include <stdio.h>
2 #include <limits.h> // provides the constant INT_MAX
3 #include <stdlib.h> // provides abs function and malloc
4 #include "Fraction.h"
5 #include <assert.h>
6
7 int gcd(int a, int b)
8 {
9   if (a == 0 && b == 0) {
10      printf("Illegal args to gcd: %d, %d\n",a,b);
11      exit(1);
12   }
13   a = abs(a);
14   b = abs(b);
15   if (a == 0)
16      return b;
17   if (b == 0)
18      return a;
19   return gcd(b,a%b);
20 }
21
22 Fraction string_to_fraction(const char *S)
23 {
24   Fraction result = {0,1};
25
26   sscanf(S,"%d/%d",&result.numer, &result.denom);
27
28   reduce_fraction(&result);
29
30   return result;
31 }
32
33 char * fraction_to_string(Fraction R)
34 {
35   char *answer = (char*)(malloc(23));
36
37   if(R.denom == 1)
38   {
39     sprintf(answer, "%d", R.numer);
40   }
41
42   else
43   {
44     sprintf(answer, "%d/%d", R.numer, R.denom);
45   }
46
47   return answer;
48 }
49
50
51 int compare_fractions(Fraction L, Fraction R)
52 {
53
54   if((L.numer * R.denom) < (L.denom * R.numer))
55     return -1;
56
57   if((L.numer * R.denom) == (L.denom * R.numer))
58     return 0;
59
60   if((L.numer * R.denom) > (L.denom * R.numer))
61     return 1;
62 }
63
64 void reduce_fraction(Fraction *R)
65 {
66   int min, i;
67
68   if(R -> numer < R -> denom)
69      min = R -> numer;
70   else
71      min = R -> denom;
72
73   for(i = min; i >= 1; i--)
74   {
75      if(R -> numer % i == 0 && R -> denom % i == 0)
76         break;
77   }
78
79   R -> numer = R -> numer / i;
80   R -> denom = R -> denom / i;
81
82 }
83
84 Fraction add_fractions(Fraction L, Fraction R)
85 {
86   Fraction result = {0,1};
87
88   result.numer = L.numer * R.denom + R.numer * L.denom;
89   result.denom = L.denom * R.denom;
90
91   reduce_fraction(&result);
92
93   return result;
94 }