[Leetcode] (Daily suppressed questions 258, everyone added)

Code

int addDigits(int num){
    
    
 if(num==0)
 {
    
    
     return false;
 }
 int ans=0;
 while(num)
 {
    
    
     ans+=num%10;
     num/=10;
 }
 return ans<10 ? ans : addDigits(ans);
}