Software-testing-foundations-homework3

题目

private static void printPrimes(int n) {

    int curPrime; //Value currently considered for primeness

    int numPrimes; // Number of primes found so far;

    boolean isPrime; //Is curPrime prime?

    int[] primes = new int[MAXPRIMES];// The list of primes.

 

    // Initialize 2 into the list of primes.

    primes[0] = 2;

    numPrimes = 1;

    curPrime = 2;

    while(numPrimes < n) {

        curPrime++; // next number to consider...

        isPrime = true;

        for(int i = 0; i <= numPrimes; i++ ) {//for each previous prime.

            if(isDvisible(primes[i],curPrime)) {//Found a divisor, curPrime is not prime.

                isPrime = false;

                break;

            }

        }

        if(isPrime) {// save it!

            primes[numPrimes] = curPrime;

            numPrimes++;

        }

    }// End while

    for(int i = 0; i < numPrimes; i++) {// print all the primes out

        System.out.println("Prime: " + primes[i] );

    }

}

1.Draw the control flow graph for the printPrime() method

 

2.Consider test cases ti = (n = 3) and t2 = ( n = 5). Although these tour the same prime paths in printPrime(), they don’t necessarily find the same faults. Design a simple fault that t2 would be more likely to discover than t1 would.

while(numPrimes < n) 改成 while(numPrimes < 4) 这样当n为4和5的时候结果是一样的,所以能发现错误,但是前者不会

3.For printPrime(), find a test case such that the corresponding test path visits the edge that connects the beginning of the while statement to the for statement without going through the body of the while loop.

printPrimes(1); 不进入循环,不符合循环条件

4.Enumerate the test requirements (Tr) for node coverage, edge coverage, and prime path coverage for the path for printPrimes().

node coverage:[1,2,3,4,5,6,7,8,2,10,11,12],[1,2,3,4,5,9,4,7,2,10,12]

edge coverage:[1,2,3,4,5,6,7,8,2,10,11,12],[1,2,3,4,5,9,4,7,2,10,12]

prime path coverage:[1,2,3,4,5,9,4,5,9,4.5,6,7,8,2,3,4,5,6,7,8,2,3,4,5,6,7,8,2,3,4,5,6,7,2,3,4,5,6,7,2,3,4,7,2,3,4,7,2,10,11,10,11,10,12]