Perfect Number

leetcode

Finally answer:

bool checkPerfectNumber(int num) {
    int sum=0;
    int t=num/2;
    if(num==0)     //especial situation
        return false;
    for(int i=1;i<=t;i++)   //if i is smaller than num/2, do this
    {    if(num%i==0)
            sum+=i;
    }
    if(sum==num)    
        return true;
    else
       return false;
}

And an awful answer:

bool checkPerfectNumber(int num){                 
       int sum=0; 
      if(num==0)
          return false;
      if (num>=99999995)     //if the number bigger than 99999995, I guess it is false
          return false;
      for(int i=1;i<num;i++){                                                                                             
          if(num%i==0)
               sum+=i;
      } 
       if(sum==num)    
           return true; 
       else          
          return false;                  
       return;
}

在此输入正文