zigzag encoding (32bits)

zigzag_encoding32.cc

#include <cstdio>
#include <iostream>
#include <bitset>
#include <cstring>
#include <limits>

int main(int argc, char** argv)
{
  const int n = atoi(argv[1]);
  std::cout << " n              = " << std::bitset<32>(n) << ", INTMAX=" << std::numeric_limits<int>::max() << ", INTMIN=" << std::numeric_limits<int>::min() << std::endl;
  unsigned int n1=n<<1;
  std::cout << " n << 1         = " << std::bitset<32>(n1) << ", decimal=" << n1 << std::endl;
  unsigned int n2=n>>31;
  std::cout << " n >> 31        = " << std::bitset<32>(n2) << ", decimal=" << n2 << std::endl;
  unsigned int n3=n1^n2;
  std::cout << " (n<<1)^(n>>31) = " << std::bitset<32>(n3) << ", decimal=" << n3 << std::endl;

  return 0;
}

yenliangl@caterpillar: ~$ ./a.out -2147483648
n = 10000000000000000000000000000000, INTMAX=2147483647, INTMIN=-2147483648
n << 1 = 00000000000000000000000000000000, decimal=0
n >> 31 = 11111111111111111111111111111111, decimal=4294967295
(n<<1)^(n>>31) = 11111111111111111111111111111111, decimal=4294967295

yenliangl@caterpillar: ~$ ./a.out 2147483647
n = 01111111111111111111111111111111, INTMAX=2147483647, INTMIN=-2147483648
n << 1 = 11111111111111111111111111111110, decimal=4294967294
n >> 31 = 00000000000000000000000000000000, decimal=0
(n<<1)^(n>>31) = 11111111111111111111111111111110, decimal=4294967294