Re: help with a logic algorithm

Thiago Adams ha scritto:

I need an algorithm that finds the possible states of variables used in "ifs"
 for instance, I need to find out possible states:
 if (a && b){
    // 'a' is true
   // 'b' is true
 }
else
{
   // 'a' maybe be true or false
   // 'b' maybe be true or false
}
 More complex:
 if (a && b || c){
   // 'a' maybe be true or false
   // 'b' maybe be true or false
   // 'c' maybe be true or false
}
else
{
   // 'a' maybe be true or false
   // 'b' maybe be true or false
   // 'c' maybe be true or false
}
 I think this algorithm may already exists.. but not finding it.
Maybe something related with predicates.
 

I'm not sure I understand exactly what you want to obtain,
but if I understand I can propose, to you, a simple idea:
#include <stdio.h>
int main()
{
     #define SFMT "a:%-5.5s b: %-5.5s c: %-5.5s\n"
     #define BIT(v, t) (v & t)
     #define TST(v) ((v) ? "true" : "false")
     unsigned char a = 1 << 0,
                   b = 1 << 1,
                   c = 1 << 2;
     for(unsigned char i = 0; i <= 7; i++)
     {
         if(BIT(i, a) && BIT(i, b) || BIT(i, c))
         {
             printf("Then: " SFMT, TST(BIT(i, a)),
                                   TST(BIT(i, b)),
                                   TST(BIT(i, c)));
         }
         else
         {
             printf("Else: " SFMT, TST(BIT(i, a)),
                                   TST(BIT(i, b)),
                                   TST(BIT(i, c)));
         }
     }
     return 0;
}
output:
Else: a:false b: false c: false
Else: a:true  b: false c: false
Else: a:false b: true  c: false
Then: a:true  b: true  c: false
Then: a:false b: false c: true
Then: a:true  b: false c: true
Then: a:false b: true  c: true
Then: a:true  b: true  c: true