#include <iostream>
#include <vector>
#include <bitset>
#include <algorithm>
/*
removeBitsAndShift(number, positions)
-------------------------------------
Removes multiple bit positions from a number and shifts the remaining bits
right to fill the gaps.
Example:
number = 1234 (0000 0000 0000 0000 0000 0100 1101 0010)
positions = {1, 3, 7}
*/
int removeBitsAndShift(int number, const std::vector<int>& positions) {
// Sort positions from highest to lowest so removals don't affect earlier ones
std::vector<int> sorted = positions;
std::sort(sorted.begin(), sorted.end(), std::greater<int>());
int result = number;
for (int pos : sorted) {
int left = result >> (pos + 1); // bits above removed bit
int right = result & ((1 << pos) - 1); // bits below removed bit
result = (left << pos) | right; // merge
}
return result;
}
/*
printBinary(n)
--------------
Prints a 32-bit binary representation of an integer.
*/
void printBinary(int n) {
std::bitset<32> bits(n);
std::string s = bits.to_string();
// Insert spaces every 4 bits
for (int i = 0; i < 32; i++) {
std::cout << s[i];
if ((i + 1) % 4 == 0) std::cout << " ";
}
}
int main() {
int number = 1234; // 0000 0000 0000 0000 0000 0100 1101 0010
std::vector<int> positions = {1, 3, 7}; // remove bits 1, 3, 7 (0 = LSB)
std::cout << "Original number in binary:\n";
printBinary(number);
int result = removeBitsAndShift(number, positions);
std::cout << "\n\nNumber after removing bits {1, 3, 7} and shifting remaining bits:\n";
printBinary(result);
std::cout << "\n\nResult as integer: " << result << std::endl;
}
/*
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
*/
