PLZ HELP..HOW TO REDUCE TIME COMPLEXITY ??

general
,
1 
#include <stdio.h>
//#include <conio.h>
int main()
{
 //clrscr();
 int t;
 long m,n,num,sum=0,lsum=0,i;
 scanf("%d",&t);
 while(t--)
 {
  scanf("%ld%ld",&m,&n);
  i=m;
  while(i<=n)
  {
   //num=i;
   while(i!=0)
   {
     num=i%10;
     i=i/10;
     if(num%2==0)
      sum=sum+2*num;
     else
      sum=sum+num;
   }
   lsum=lsum+(sum%10);
   i++;
  }
 }
 printf("\n%ld",lsum);
 return 0;
 }
2

can you state the question for which you have coded this.

3

instead of i=i/10 use 1/=10;
sum+=(num<<1);
and a few more like this,but it won’t really help much

give the link of the file you have problem with or the question so we can try too

4

while(t–), there is no condition declared within while loop

5

it’s c so when t-- will be 0 it’ll exit

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6

Can you state the problem you are trying to solve? Also mention what is your current approach. Seems like a poorly framed question (?)

7

this is the question…http://www.codechef.com/problems/LASTDIG

8

You are dividing the i: i/=10. This means that i is always set back to 1 at the end of the loop. You should use a temporary variable for the dividing. Like this:

 while(i<=n){
     int temp=i;
     while(temp!=0){
         num=temp%10;
         temp/=10;
     }
     i++;
 }

P.S.: There are many other errors in your code in solving the stated problem.But they are not connected with the infinite looping.

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