21394. Ohani And The Series - TLE

[rkc_14]

me too getting TLE again and again, help me please.

#include<stdio.h>
#define m 1000000007
long long int power(int n)
{
            long long int ans=1,i;
     for(i=1;i<=n;i++)
            {
              ans=(2*ans)%m;

        }
        return ans;
}
int main()
{
   int t,i,x,n;
   scanf("%d",&t);
   for(i=1;i<=t;i++)
   {
      //long long int n;
      scanf("%d",&n);
      if(n==1)
      printf("Case %d: 1\n",i);
      else
      {
               long long int x=((n+1)*power(n-2))%m;
           printf("Case %d: %lld\n",i,x)  ;
  }
   }
   return 0;
}

[vamsi_ism]

@rkc_14 you can't afford to calculate power every time(that too using a O(n) process). Use exponentiation by squaring(likely to pass the TL in C++) or do pre-computation.