/*
remove_bits_and_shift(number, positions)
----------------------------------------
Removes multiple bit positions from a number and shifts the remaining bits
right to fill the gaps.
Important:
Bits must be removed from highest → lowest position.
Otherwise earlier removals shift the positions of later ones.
*/
fn remove_bits_and_shift(number: i32, positions: &[i32]) -> i32 {
// Sort positions descending
let mut sorted: Vec<i32> = positions.to_vec();
sorted.sort_by(|a, b| b.cmp(a));
let mut result: i32 = number;
for &pos in &sorted {
let left: i32 = result >> (pos + 1); // bits above removed bit
let right: i32 = result & ((1 << pos) - 1); // bits below removed bit
result = (left << pos) | right; // merge
}
result
}
/*
print_binary(n)
---------------
Prints a 32-bit binary representation of an integer.
*/
fn print_binary(n: i32) {
let binary: String = format!("{:032b}", n);
let grouped: String = binary
.as_bytes()
.chunks(4)
.map(|chunk| std::str::from_utf8(chunk).unwrap())
.collect::<Vec<&str>>()
.join(" ");
println!("{}", grouped);
}
fn main() {
let number: i32 = 1234; // 0000 0000 0000 0000 0000 0100 1101 0010
let positions: [i32; 3] = [1, 3, 7]; // remove bits 1, 3, 7 (0 = LSB)
println!("Original number in binary:");
print_binary(number);
let result: i32 = remove_bits_and_shift(number, &positions);
println!("\nNumber after removing bits {{1, 3, 7}} and shifting remaining bits:");
print_binary(result);
println!("\nResult as integer: {}", result);
}
/*
run:
Original number in binary:
0000 0000 0000 0000 0000 0100 1101 0010
Number after removing bits {1, 3, 7} and shifting remaining bits:
0000 0000 0000 0000 0000 0000 1001 0100
Result as integer: 148
*/
