Question

• Why, in many situations, must integer programming be used instead of linear programming that allows non-integer variables? What is the purpose of 0-1 variables? What sort of problem would use them?

Answer 1

In a program , function can call other function, In tern calling function checks the return value from function being called. Depending on the value being returned , logic of the function which is calling this function depends. That kind of the functions should use the integer return values mainly for indicating success or failure.You can have 0 to indicate function successfully executed and 1 to indicate failure. Sometime you can use 0 as false value and 1 as true value returning from function. It is easy to compare integers than the non integers. Consider the below function

int isOdd(int num)

{

if(num%2 == 1)

return 1; //which indicates num is odd

else

return 0; //indicates num is even

}

//now consider the main program which calls isOdd function

int main()

{

if(isOdd(3) == 1)

printf("3 is odd number\n");

else

printf("3 is not odd number\n");

}

Here in main , depending on the return value from isOdd function , main prints the results.