finding the middle number in C

THIS IS HOMEWORK. thought i'd let you know. if you could point me in the direction that would help me discover why this error is happening, i'd appreciate it. http://pastebin.com/hDUpfrsu is my current code (included below). why does it return ONE when i enter (in this order) 5, 6, 7 or other sequences?

#include <stdio.h>
#include <simpio.h>
#include <genlib.h>

/* finds the minimum among three integers using minimal amount of relational operations */

int main()
{
    int myNumbers[2];
    bool l开发者_StackOverflowowest;
    printf("Enter the first integer...\t");
    myNumbers[0] = GetInteger();
    printf("Enter the second integer...\t");
    myNumbers[1] = GetInteger();
    printf("Enter the third integer...\t");
    myNumbers[2] = GetInteger();

    if (myNumbers[0] < myNumbers[1] && myNumbers[0] < myNumbers[2])
    {
       lowest = myNumbers[0];
    }

    if (myNumbers[0] > myNumbers[1] && myNumbers[1] < myNumbers[2])
    {
       lowest = myNumbers[1];
    }

    if (myNumbers[0] > myNumbers[2] && myNumbers[1] > myNumbers[2])
    {
       lowest = myNumbers[2];
    }

    printf("\n%d", lowest);
    getchar();
    return 0;

}

A few issues:

• lowest is defined as a bool, it should be an int with how you are using it

• myNumbers[2] is an array of size 2, it can only hold 2 numbers. Change the size declaration to 3.

• Consider what would happen if two or more of the values were equal...

Replace

bool lowest;

by

int lowest;

since you want to store an integer number in 'lowest', not a boolean.

lowest is a bool. Shouldn't it be something larger?

The answer to your question is that, as many others have pointed out, you're using lowest as a boolean type, instead of a number type, such as int, which would be in harmony with the rest of your program.

bool lowest;

Boolean types, as expected, can hold basically two states: true and false. For historical reasons (i.e., mainly because of the C inheritance), boolean values have been associated with integer numbers, for which 0 meant false and any other value meant true.

That's why the Boolean type is still compatible with integers (that's a way of saying this), and when you assign it to a zero, then it holds false. If you assign to it any other int value, it will hold true. This is happening in lines such as this one:

lowest = myNumbers[0];

Finally, when you execute:

printf("\n%d", lowest);

The inverse process takes place, and true is converted to int (since you specified %d in the printf format string), and true is converted to 1, which is the default integer value for true in the bool type when its integer value: (int) true (in your program: (int) lowest) is asked.

As you can imagine, more than 90% of times the input integer values are going to be different from zero, that's why you are obtaining 1, no matter the input.

Adding to other's answers.

You have:

int myNumbers[2];
...
myNumbers[2] = GetInteger();

this is incorrect. myNumbers is an array of 2 elements and valid array indices are 0 and 1. Since you want to store 3 elements in the array change its size to 3.

Warning: Your array isn't big enough. When you declare an array, the index isn't the maximum index of the array, but the number of elements, which is the maximum index + 1.

You can use Ternary Operator ( ? :) To find lowest number or highest b/w three numbers with minimum number of relational operators(As you said).

int low, lowest;
low = (number[0] < number[1]) ? number[0] : number[1];
lowest =(low < number[2]) ? low : number[2];
printf("%d",lowest);

Others have pointed about the obvious flaws in the program (viz size of array, data type of the result). Here is a bit which will make you understand the indexing of arrays, specifically why they start from zero?

PS: I like the top rated answer but i advise you to read the entire post.

This question has already been answered so I will post a solution that is much simpler:

int lowest = myNumbers[0];
if (myNumbers[1] < lowest)
{
    lowest = myNumbers[1];
}
if (myNumbers[2] < lowest)
{
    lowest = myNumbers[2];
}
printf("lowest value is: %d\n", lowest);

You only need that many conditions!