Check for missing number in sequence

Question

I have an List which contains 1,2,4,7,9 for example.

I have a range from 0 to 10.

Is there a way to determine what numbers are missin

Answer 1

Create an array of num items

const int numItems = 1000;
bool found[numItems] = new bool[numItems];


List list;

PopulateList(list);

list.ForEach( i => found[i] = true );

// now iterate found for the numbers found
for(int count = 0; i < numItems; ++numItems){
  Console.WriteList("Item {0} is {1}", count, found[count] ? "there" : "not there");
}