from java and algorithms

1-Solving a problem requires running an O(N) algorithm and then afterwards a second O(N) algorithm. What is the total cost of solving the problem?

2-

What is the runtime of the following code fragment

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

sum++;

}

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

sum++;

}

3-

What is the runtime of the following code fragment

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

for( int j = 0; j < i; j++ ){

sum++;

}

}

4-Suppose that when the capacity of an ArrayList is increased, it is always doubled. If an ArrayList stores N items, and started with an initial capacity of 1, what is the maximum number of times that an ArrayLists capacity could have been increased?

5-

What is the runtime of the following code fragment

for( int i = 1; i < n; i = i * 2 ){

sum++;

}

6-

What is the runtime of the following code fragment

for( int i = 0; i < n; i += 2 ){

sum++;

}