图覆盖

1. 综述

图覆盖

2. 练习题

已知程序：

/*******************************************************

* Finds and prints n prime integers

* Jeff Offutt, Spring 2003

******************************************************/

public static void printPrimes (intn)

{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 prime numbers.//Initialize 2 into the list of primes.

primes [0] = 2;

numPrimes= 1;

curPrime= 2;while (numPrimes

{

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

isPrime = true;for (int i = 0; i <= numPrimes-1; i++)

{//for each previous prime.

if(isDivisable(primes[i],curPrime))

{//Found a divisor, curPrime is not prime.

isPrime = false;break; //out of loop through primes.

}

}if(isPrime)

{//save it!

primes[numPrimes] =curPrime;

numPrimes++;

}

}//End while//Print all the primes out.

for (int i = 0; i <= numPrimes-1; i++)

{

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

}

}//end printPrimes

(a). printPrimes方法的控制流图为：

(b). 对于测试用例t1=(n=3)和t2=(n=5)，MAXPRIMES = 4时，t1不能检查出错误，而t2则会发生数组越界错。

(c). 对于测试用例t3=(n=1)，测试路径不经过while的循环体。

(d). 针对printPrimes()的图列举每个节点覆盖、边覆盖和主路径覆盖的测试需求。

节点覆盖：TR={1,2,3,4,5,6,7,8,9,10,11,12,13,14}

边覆盖：TR={(1,2), (2,3), (2,10), (3,4), (4,5), (5,6), (5,8), (6,5), (6,7), (7,8), (8,2), (9,2), (10,11), (11,12), (11,14), (12,13), (13,11)}

主路径覆盖：TR={

(1,2,3,4,5,6,7),

(1,2,3,4,5,6,8,9,10,11),

(1,2,3,4,5,6,8,9,11),

(1,2,3,4,5,9,10,11),

(1,2,3,4,5,9,11),

(1,2,12,13,14,15),

(1,2,12,16),

(2,3,4,5,6,8,9,10,11,2),

(2,3,4,5,6,8,9,11,2),

(2,3,4,5,9,10,11,2),

(2,3,4,5,9,11,2),

(3,4,5,6,8,9,10,11,2,12,13,14,15),

(3,4,5,6,8,9,11,2,12,13,14,15),

(3,4,5,6,8,9,10,11,2,12,13,16),

(3,4,5,6,8,9,11,2,12,13,16),

(3,4,5,9,10,11,2,12,13,14,15),

(3,4,5,9,11,2,12,13,14,15),

(3,4,5,9,10,11,2,12,13,16),

(3,4,5,9,11,2,12,13,16),

(5,6,7,5),

(6,7,5,9,10,11,2,12,13,14,15),

(6,7,5,9,11,2,12,13,14,15),

(6,7,5,9,10,11,2,12,13,16),

(6,7,5,9,11,2,12,13,16),

(13,14,15,13),

(14,15,13,16)

}