factorial.cpp
//factorial.cpp #include <iostream> using namespace std; //include a function prototype so the compiler knows that factorial has been declared int factorial (int n); //a test program for the factorial function int main () { //input a value for the factorial computation cout << "Enter a positive integer n: "; //declare n as an integer before it is used in a program statement int n; //use standard console input object cin >> n; //make sure n is greater than zero if (n >=0) cout << "factorial(" << n << ") = " //display answer << factorial (n) << endl; else { cerr << "factorial(" << n << ") undefined" << endl; return 1; } return 0; } //A function to compute the factorial of its argument -- argument must be positive integer int factorial(int n) { //declare local variable ans int ans =1; while (n > 1) { ans = ans * n; n = n-1; } return ans; }
C:\classes\ece538\work>factorial Enter a positive integer n: 4 factorial(4) = 24
Maintained by John Loomis, updated Sun Dec 31 17:09:35 2006