Wa in NXS3

1

https://www.codechef.com/viewsolution/29849687
I used binary exponentiation to compute 2^n

2

your power function is wrong

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long long int modpower(long long int b,long long int po, long long int p){
    long long int ans=1;
    while(po){
        if(po%2){
            ans*=b;
            ans%=p;
        }
        b*=b;
        b%=p;
        po/=2;
    }
    return ans;
}

It returns b^{po} mod p
Here’s my exponentiation function template :slightly_smiling_face:

4

in one line:
inline ll powmod(ll a,ll b,ll mod) {ll res=1;a%=mod; for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;} :wink:

5

That doesn’t look like one line to me :confused:

6

ok…a bit forced I know. By the way…your template have a problem. What’s the output for this?

b= 1e18
po =10
p=1e9+7

7

I do b%p before putting it in so…
Also I just checked, he solved the question 19 hours ago :sweat_smile:

1 Like
8

Never mind the test cases are visible now.

9

Thanks for pointing out everyone i realised that i made a mistake after some time in my power function

10

i was reading, not an easy cake. I coud see your code failed in this testcase for example

7
20 55 81 6 22 50 93

1 Like
11

I forgot to insert 0th element in map.
And still it passes pretests as well as ~20 test cases :pensive:
Thanks :smiley:

1 Like