KTH ROOT probelm

#1

sir , I m not able to solve this problem .

#2

Constraints are very big
you have to use newton’s method
Hint
according to newton’s method
x(K+1) = x(K) – f(x) / f’(x)
here f(x) = x^(N) – A
so f’(x) = N*x^(N - 1)
and x(K) denoted the value of x at Kth iteration
putting the values and simplifying we get,
x(K + 1) = (1 / N) * ((N - 1) * x(K) + A / x(K) ^ (N - 1))

or use can use this trick

int t=float(1)/k;
cout<<pow(n,t);