Question

Please explain this code line by line

void printperm(int *A,int n,int rem,int j)
{
   if(n==1)
      {
       for(int k=0;k<j;k++)
       cout<<A[k]<<" + ";
       cout<<rem<<"\n";
       return;
      }
    for(int i=0;i<=rem;i++)
   {
         if(i<=rem)
         A[j]=i;
         printperm(A,n-1,rem-i,j+1);
   }
}

Answer 1

/*There int *A is integer type pointer that store the address of array A,

int n int rem or int j are the local variable/parameterized variable */

void printperm(int *A,int n,int rem,int j)
{
   if(n==1) //check if n is equal to 1 if true then execute if block,
      {
       for(int k=0;k<j;k++) //execute for loop from k = 0 to less then to j,
       cout<<A[k]<<" + ";  //print the array value with + symbol,
       cout<<rem<<"\n"; //print rem value with new line,
       return;
      }
    for(int i=0;i<=rem;i++) // execute for loop from I = 0 to less then rem value,
   {
         if(i<=rem) //execute if block till when i is less then rem,
         A[j]=i; //assign i value to array jth index,
         printperm(A,n-1,rem-i,j+1); //here function is calling to itself, this is knowing as recurrsive function,
   }
}