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Computing for the minimum/maximum values between two integers is a fairly common task in many computer programming problems. This can easily be done with branching (i.e. the use of the if-else conditional statements).

Here’s a trick in C programming that computes the minimum/maximum between two integers WITHOUT BRANCHING (and using math.h’s built-in min/max function). Note that this makes use of the AND (&) bitwise operator and XOR (^) bitwise operator.

//start
int a = 300;
int b = 200;
int min;
int max;

min = b ^ ((a ^ b) & -(a < b)); //gives min value
max = a ^ ((a ^ b) & -(a < b)); //gives max value

printf(”%d\n”, min);
printf(”%d\n”, max);
//end

One of the very first programming exercise a beginner programmer would encounter is swapping the values of two variables. The solution is pretty much trivial:

//start
int a = 1;
int b = 2;
int temp;

printf(”Values before swapping a = %d b = %d\n”, a,b);

temp = a;
a = b;
b = temp;

printf(”Values after swapping a = %d b = %d”, a,b);
//end

Here’s a trick to swap the values of two integer/short/long variables WITHOUT USING A TEMPORARY VARIABLE. Note that this implementation makes use of the XOR bitwise operator (^).

//start
int a = 1;
int b = 2;

printf(”Values before swapping a = %d b = %d\n”, a,b);

a = a ^ b;
b = b ^ a;
a = a ^ b;

printf(”Values after swapping a = %d b = %d”, a,b);
//end

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