1.구구단 짝수단만출력 단,2단은 2*2까지, 4단은 4*4까지, 이런식으로 출력하자.

#include <stdio.h>
#include <stdlib.h>
int main(void)
{
    int dan,is;
    for(dan=2;dan<10;dan++)
    {
                          
         if(dan%2!=0) continue;    
         for(is=1;is<10;is++)
         {
            if(dan<is) break;
            printf("%d*%d=%d\n",dan,is,dan*is);
        
        }//for is<10
        printf("\n");
      
   }//if dan<0
                               
                               
                               
    system("pause");
    return 0;
}
2.ZA+AZ=99출력하기

 

#include <stdio.h>
#include <stdlib.h>
int main(void)
{
    int A,Z;
    int result;
    for(Z=0;Z<10;Z++)
    {
         for(A=0;A<10;A++)
         {
              if(A==Z) continue;
              result=(A*10+Z)+(Z*10+A);
              if(result==99)
              printf("%d%d+%d%d=%d\n",Z,A,A,Z,result);
              }
              }
    system("pause");
    return 0;
}