Why it is showing execution timed out

Question

How to solve the problem
https://code.sololearn.com/ceibA9RBz9eg/?ref=app

Answer 1

Why here j <= 2*j + 1? Here should be a
for(j=1;j<=2*j+1;j++)
//change above loop which is 2nd loop of your program with below loop
for(j = 1; j <= 2 * a + 1; j++)
it will work fine.