Consider the code segments below and give the O estimates for each segment. Be sure to explain how you arrived at your estimates. (a) [12 pts.]

(a) Sum = 0;

(b) for (i = 0; i < N; i++)

(c) for (j = 0; j < N*N; j++)

(d) Sum++;

(b) [13 pts.]

(a) Sum = 0;

(b) for (i = 0; i < N; i++)

(c) for (j = 0; j < i*i; j++)

(d) for (k = 0; k < j; k++)

(e) Sum++;