1 //第二题
  2 
  3 #include <stdio.h>
  4 
  5 int main (void){
  6     int p,q;
  7     
  8     printf ("Please enter two integers: ");
  9     scanf ("%i %i", &p, &q);
 10     if (p % q ==0)
 11         printf ("Right!"\n);
 12     else
 13         printf ("Bad news!\n");
 14     
 15     return 0;
 16 }
 17 
 18 //第三题
 19 
 20 #include <stdio.h>
 21 
 22 int main (void){
 23     float p, q;
 24     
 25     printf ("Please enter two integers: ");
 26     scanf ("%i %i", &p, &q);
 27     
 28     if (q==0)
 29         printf ("The integer is zero.\n");
 30     else
 31         printf ("The ending is %.3f.\n", p / q);
 32     
 33     return 0;
 34 }
 35 
 36 //第四题
 37 //不会做
 38 
 39 #include <stdio.h>
 40 
 41 int main (void){
 42     int number, operator,counter;
 43     
 44     printf ("Please enter a number and a operator: ");
 45     scanf ("%i %i", &number, &operator);
 46     for (counter=1;counter<=10;++counter){
 47         
 48     }
 49     return 0;
 50 }
 51 
 52 //第五题
 53 
 54 #include <stdio.h>
 55 #include <stdbool.h>
 56 
 57 int main (void){
 58     int number,right_digit;
 59     bool isNegative = false;
 60     
 61     //save the integer in number
 62     printf ("Please enter a integer: ");
 63     scanf ("%i", &number);
 64     
 65     if (number < 0){
 66         number = -number;
 67         isNegative = true;
 68     }
 69     //display the number in adverse order
 70     do{
 71         right_digit = number % 10;
 72         printf ("%i", right_digit);
 73         number /= 10;
 74     }
 75     while (number != 0);
 76         
 77     if (isNegative == true)
 78         printf("-");
 79         
 80     printf ("\n");
 81     
 82     return 0;
 83 }
 84 
 85 //第七题
 86 
 87 #include <stdio.h>
 88 #include <stdbool.h>
 89 
 90 int main (void){
 91     int p,d;
 92     bool isPrime;
 93     
 94     printf ("2 ");
 95     
 96     for (p = 3; p <= 50; p+=2){
 97         isPrime = true;
 98         
 99         for (d = 3; d < p && isPrime == true; d+=2)
100             if (p % d == 0)
101                 isPrime = false;
102             
103         if (isPrime != false)
104             printf ("%i ", p);
105     }
106     
107     printf ("\n");
108     
109     return 0;
110     
111 }