Name (print) ___________________________________ Lab Section you attend______________

#### CSE131 Module 3 Extension

Iteration

Take-home, due 25 Sept 2008
in Lab

Consider the iterative method below:
// return the product of a and b, which must be supplied as positive integers.
public static int mpy(int a, int b) {
int ans = 0,
i = b;
while (i != 0) {
i = i - 1;
ans = ans + a;
}
return ans;
}

Develop and use a loop invariant to prove that the method computes
the appropriate product. You may interact only with the professor on
this problem (by IM or in person). You must be able to explain your
proof in person during Lab or Studio session to the professor.