You need to know two formula:

1. sum of arithmetic series:
  1+2+3+.....+n = n(n+1)/2
2. sum of geometric series:
  1 + a + a² + a³ +..... + aⁿ = (aⁿ⁺¹-1)/(a-1)
    1 + a + a² + a³ +..... + to infinity term = 1/(1-a)
3. Special formula:
  1²+2²+3²+....+n²=n(n+1)(2n+1)/6
  1³+2³+3³+.....+n³=n²(n+1)²/4

• "for" loop
• Nested "for" loop
• Consecutive statements
• "if/else" statements  -   Click here to see an example.
• recursive procedures

• Write a program to evaluate a recursive function

For example, your assignment 2 or assignment 5
• Give an analysis of the running time and conclude it in Big-Oh concept.

Examples:
 

int factorial(int n)  {     if (n<= 1)        return 1;     else return (n *factorial(n - 1));  }

T(1) = 2 T(n) = 1+T(n-1)+2 ..... ..... You will get    T(n) = O(n)

void print(int x) {     if (x < 4)       cout<<x;     else      {        print(x/4);        cout<<x%4;       }     cout<<endl; }

T(n)=1+T(n/4)+2 ..... ..... ..... ...... You will get      T(n) = O(log n)