1.IP地址判断是否正确 2.一段字符空格和字母，数字个数 3.给整数输出二进制

1.IP地址判断是否正确
2.一段字符空格和字母，数字个数
3.给整数输出二进制

#include <stdio.h>
#include<iostream>
using namespace std;
int main()
{
	int n, a, b, c, d;
	scanf("%d", &n);
	while (n--){
		scanf("%d.%d.%d.%d", &a, &b, &c, &d);
		if (a < 0 || b < 0 || c < 0 || d < 0 || a > 255 || b > 255 || c > 255 || d > 255)
			printf("No!
");
		else
			printf("Yes!
");
	}
	system("pause");
	return 0;
}



#include <iostream>

using namespace std;

int main()

{
	
    char c;
	
    int letters = 0, space = 0, digit = 0, others = 0;
	
    while ((c = getchar())!= '
')

	{
		
        if (c >= 'a'&&c <= 'z' || c >= 'A'&&c <= 'Z')
		
	letters++;
		
        else if (c == ' ')
	
         space++;
		
        else if (c >= '0'&&c <= '9')

	 digit++;
		
        else
		
        others++;
	
printf("char=%d space=%d digit=%d others=%d
", letters, space, digit, others);
	
system("pause");
	
return 0;

}



#include <iostream> 
using namespace std;
int main()
{
	int num ;
	cin >> num;
	while(num)
	{
		cout << (num&1);
		num = num >> 1;//把num转换成二进制表示后所有位向后移动一位，高位补0
	}
	cout <<endl;
	system("pause");
	return 0;
}