Integer division c++
Integer division problem definition
Given the following function which computes integer division. Debug the code and identify the major bugs. Modify the code to fix those bugs. Assume all integer variables are within range and no overflow is about to happen.
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int Division(int numerator, int denominator) { int quotient = 0; while (numerator > denominator) { quotient++; numerator -= denominator; } return quotient; } |
Integer division explained
(1) If the numerator is equal to the denominator the function must return 1 but in this case it returns 0 which is wrong (2) if the denominator is 0 then the while will not end if the numerator is positive. If the numerator is negative then the function will return 0 as the final result which is wrong as we all know that division by zero is not allowed (3) If the numerator is positive and the denominator is negative then the while loop will not end because the numerator will keep increasing.
The solution is to operate on positive integers then return the right sign at the end based on the sign of input integers. We also need to handle the case of division by zero and the case when numerator is equal to denominator.
Integer division algorithm
Here is an integer division example in C++
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// Integer division calculator int Division(int numerator, int denominator) { //Divide by zero special case if (denominator == 0) { return -999999; } //Both are equal special case if (numerator == denominator) { return 1; } int quotient = 0; //Get the sign of the division int sign = 1; if (numerator * denominator < 0) { sign = -1; } //Convert to positive or you can use //built in ABS function if (numerator < 0) { numerator = -1 * numerator; } if (denominator < 0) { denominator = -1 * denominator; } while (numerator > denominator) { quotient++; numerator -= denominator; } return sign * quotient; } |
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About Author
Mohammed Abualrob
Software Engineer @ Cisco
U should also add equality to ur while loop:
while (numerator >= denominator)
This is for cases where the numerator = dominator within the loop…
example: 10/5
numerator= 10
after first loop numerator =5!
but quotient still = 1.