What is the complexity of the code:

for (i=0; i < n; i++)

for (j=0; j < n; j++)

for (k=0; k < n; k++)

x++

What is the complexity of the code:

for (i=0; i < n; i++)

for (j=0; j< n; j++)

x++;

What is the complexity of the code:

for (i=0; i < n; i++)

for (j=0; j < n/2; j++)

x++;