算法思想

一：Good at to take advantage of computer super calculate ability

       

        sametimes we use math to analyze and  resolve prolem very difficulty,

        if use computer , the problem can be very simple.beacuse we can use exhaustive method.

        we only need to find a  situation for satisfying the problemrequire.

         for example:       

             To find the numbers that them sum equal you input number

                if you use pure math to resolve  the problem it is  very difficulty.

                but now we can take advantage of computer super calculate ability,the problem can be so easy     

          public int AllCount(int sum) 

          {

               int count = 0;

               for(int i=0;i<=9;i++)

                   for(int j=0;j<=9;j++)

                      for(int k=0;k<=9;k++)

                      {

                          if ((i + j + k) == sum) //satisfy it require

                          { count++; }

                       }

                  return count;

           }

二：First Sort ,Then Calculate

     some problem  if you to sort it first ,it will becomes very simple