prime1 - tle

[kalpitagarwal]

thanks for quick answr "leppy"

#include<math.h>
#include<stdio.h>
int isPrime(int k); 
    int j;
        int isPrime(int k) 
                {
        for(j=2; j<=(int)sqrt(k); j++) 
                        {
                        if(k%j==0)
                return 0;
                        }
                        return 1;
                }
int main()
{
        int u,i,t,m,n,k;        
         scanf("%d", &t);
         while(t--)
        {       
                scanf("%d %d", &m, &n);
                for(i=m;i<=n;i++)
                {
                        u = isPrime(i);
                        if (u == 1)
                        printf("%d\n", i);
                }
        }
        return 0;
}

this is code for prime Generator problem. I am getting time limit exceeded .. what should i do ..?? i dun understand how to decrease time.. i think my program is fast enough... where is the problem

[leppyr64]

It is not fast enough unfortunately. Your code does not run in 1s on any PC for the worst possible test case. Can you figure out what that test case is?

[kalpitagarwal]

how can i figure out wht the test case is.. i dun knw much about time limits. plz tell me what shud i do to improve my programs response time

[leppyr64]

For what number do you think isPrime would take the longest to run?

[kalpitagarwal]

i think it will take for 1-100000
but how shud i decrease the response time??

[leppyr64]

For a number to be prime is must be (fill in this blank).