100 - The 3n + 1 problem

[mf]

cout<<"enter two number i,j:"; //enter two number as it's range

cout<<"maximum cycle length:"<<max<<endl; //output maximum cycle length

Don't output anything that you aren't explicitely asked to output.
If you give your program the input, given in "Sample Input" section, it must produce exactly the same output as in "Sample Output".

is enter 4 pair of value in same time??
and output the four pair of value in same time??

That's correct.

Check http://acm.uva.es/p/data/p100.c.html for a sample accepted solution.

[toyman]

Check http://acm.uva.es/p/data/p100.c.html for a sample accepted solution.[/quote]

Your code

while (scanf("%d %d\n",&m,&n)==2){

why shoule "scanf("%d %d\n",&m,&n)==2"....

and my code...

Code: Select all

#include<iostream>
using namespace std;
int compute(int i);   //define function                 
main()
{
    int h,i,j,max,swap; //define variables                     
    while(cin>>i>>j){ 
      if (i > j){
	     swap = i;
	     i = j;
	     j = swap;
	  }
     max = compute(i);
     for(h=i+1;h<j;h++){   
        swap=compute(h);
        if(swap>max){            
            max=swap;             
        }           
     }
     cout<<i<<" "<<j<<" "<<max<<endl;  //output maximum cycle length
    }
}
int compute(int i)
{
    int count=1;     
        while(i!=1){      
            if(i%2)        
                i=3*i+1;   
            else           
                i=i/2;     
            count++;       
        }
        return count;     
    return 0;
}

My ouput is
1 10
1 10 20
100 200
100 200 125
....

--
I have poor ability in coding@@

[mf]

Your new code is almost correct. But please note this sentence in the problem statement:

The integers i and j must appear in the output in the same order in which they appeared in the input

(Thus, output for input "200 100" should be "200 100 125".)

[toyman]

Code: Select all

#include<iostream>
using namespace std;
int compute(int i);  //define function                 
main()
{
    int max[20],ioo[20],joo[20];//define variables                        
    int swap,x=0,times=0,k;
    int h,i=0,j=0;
    while((cin>>i>>j)){ 
       ioo[times]=i;
	   joo[times]=j;
       if (i > j){
	      swap = i;
	      i = j;
	      j = swap;
	   }
       max[times] = compute(i);
       for(h=i+1;h<j;h++){   
          swap=compute(h);
          if(swap>max[times]){            
              max[times]=swap;             
          }           
       }
       times++;
    }
    //cout<<"The output"<<endl;
    for(k=0;k<times;k++){
                cout<<ioo[k]<<" "<<joo[k]<<" "<<max[k]<<endl;  
    }
    system("pause");
    return 0;
}
int compute(int i)
{
    int count=1;     
        while(i!=1){      
            if(i%2)        
                i=3*i+1;   
            else           
                i=i/2;     
            count++;       
        }
        return count;     
    return 0;
}

Runtime Error

Your program has died with signal 11 (SIGSEGV). Meaning:

Invalid memory reference

Before crash, it ran during 4.162 seconds.

My input is

1 10
10 1
100 200
201 210
22222222222

My output is

1 10 20
10 1 20
100 200 125
201 210 89

Is what my thought match the question's answer ???
This what i want to know?
Maybe i have wrong idea for this question!!

[mf]

You got runtime error because there are more than 20 test cases in the input.

Your previous code is quite working, as I said. Just do cout<<i<<" "<<j<<" "; before swapping i and j, and change the condition of the for-loop to "h<=j":

Code: Select all

int main()
{
    int h,i,j,max,swap;
    while(cin>>i>>j){
      cout<<i<<" "<<j<<" ";     // outputs i and j in their original order
      if (i > j){
        swap = i;
        i = j;
        j = swap;
      }
      max = compute(i);
      for(h=i+1;h<=j;h++){    // checks numbers between i+1 and j inclusive
         swap=compute(h);
         if(swap>max){           
             max=swap;             
         }           
      }
      cout<<max<<endl;
    }
}
...

[toyman]

3QQQ~~
My question have solved!!!
Thank your help!!

[diego andres de barros]

instead of while (scanf("%ld %ld",&i,&j)!=EOF)

the correct is while (scanf("%ld %ld",&i,&j)==2)

[lck]

Why it take so long to calculate the answer in haskell while only one sec in c??

Code: Select all

f 1 = 1
f n = 1 +
    if even n
        then f $ div n 2
        else f $ n * 3 + 1
longCyLn i j = maximum $ map f [i..j]
putStrLn longCyLn 1 4000

[Chiech]

#include<iostream.h>

void main()
{
unsigned long i,i1,j,j1,cup;
long m;

do
{
cin>>i>>j;
}while(i<=0||i>1000000||j<=0||j>1000000);

i1=i;j1=j;
m=j-i+1;

if(m<=0)
{
m=i-j+1;
cup=i,i=j,j=cup;
}
else
{
cup=i;
}
unsigned long *a1_array=new unsigned long [j*3];
unsigned long *a2_array=new unsigned long [j*3];
unsigned long n,x,y=1;

start:
x=1,n=1;cup=i;
for(x=1;;x++)
{
*(a1_array+x)=cup;

if(cup==1)
{
*(a2_array+y)=n;
y++;
i++;
if(i>j)
{
goto end;
}
goto start;
}
else if(*(a1_array+x)%2==0)
{
n++;
cup=*(a1_array+x)/2;
continue;
}
else
{
cup=3*cup+1;
n++;
continue;
}
}
end:
unsigned long z;
*(a2_array)=0;

for(z=1;z<y;z++)
{
if(*(a2_array)<*(a2_array+z)){*(a2_array)=*(a2_array+z);}
}
cout<<i1<<" "<<j1<<" "<<*(a2_array)<<"\n";
delete[] a1_array;
delete[] a2_array;

}


This is my code~please help me ~I get wa~"~

[jtmh]

instead of while (scanf("%ld %ld",&i,&j)!=EOF)

the correct is while (scanf("%ld %ld",&i,&j)==2)

Both work, actually.

[newton]

Code: Select all

       Accepted     so    Deleted!

[898989]

Salamo Aleko
One of the ways to get ac is to check on range on fly
make a function that get a cycle of a number

Then in main() procees directly on the range.....Then try to solve 371

[alternate]

scanf returns an integer containing the number of items read. EOF is returned if no items can be read therefore in this case it's better to compare to the number of items you require in case only one of two are input. Although, you could argue that you know the input is valid in this case so comparing to EOF will also work.

[alternate]

Loop between i and j for each input and update max to n when n is greater than max.

[jtmh]

I agree.