/**

  • 输入一个整数，输出该数二进制表示中1的个数。其中负数用补码表示。
  • /
    public class Text11
    {
    public int NumberOf1(int n)
    {
      int count = 0;
  while (n != 0) {
      ++count;
      n = (n - 1) & n;
  }
  return count;
    }
    public int NumberOf1V2(int n)
    {
      char[] c=Integer.toBinaryString(n).toCharArray();
  int count=0;
  for (int i = 0; i < c.length; i++) {
      if (c[i]=='1') {
          count++;
      }
  }
  return count;
    }
    public int NumberOf1V3(int n)
    {
      String s=Integer.toBinaryString(n);
  int count=0;
  for (int i = 0; i < s.length(); i++) {
      if (s.charAt(i)=='1') {
          count++;
      }
  }
  return count;
    }
    }