1 /*******************************************************
2 * Finds and prints n prime integers
3 * Jeff Offutt, Spring 2003
4 ******************************************************/
5 public static void printPrimes (int n)
6 {
7 int curPrime; // Value currently considered for primeness
8 int numPrimes; // Number of primes found so far.
9 boolean isPrime; // Is curPrime prime?
10 int [] primes = new int [MAXPRIMES]; // The list of prime numbers.
11
12 // Initialize 2 into the list of primes.
13 primes [0] = 2;
14 numPrimes = 1;
15 curPrime = 2;
16 while (numPrimes < n)
17 {
18 curPrime++; // next number to consider ...
19 isPrime = true;
20 for (int i = 0; i <= numPrimes-1; i++)
21 { // for each previous prime.
22 if (isDivisible(primes[i], curPrime))
23 { // Found a divisor, curPrime is not prime.
24 isPrime = false;
25 break; // out of loop through primes.
26 }
27 }
28 if (isPrime)
29 { // save it!
30 primes[numPrimes] = curPrime;
31 numPrimes++;
32 }
33 } // End while
34
35 // Print all the primes out.
36 for (int i = 0; i <= numPrimes-1; i++)
37 {
38 System.out.println ("Prime: " + primes[i]);
39 }
40 } // end printPrimes
a. 画出函数的控制流图
b. 设计一个t2=(n=5)能发现但t1=(n=3)不能发现的错误
如果这个函数的第22行 if (isDivisible(primes[i], curPrime))误写成了if (isDivisible(primes[0], curPrime))，即对以后的每个数是否是素数的检测，只检查它是否能被2整除。当n = 3时，找出的素数为2,3,5 没有出现错误；但是当n = 5时，找出的素数为2,3,5,7,9 出现错误
c. 寻找一组不经过while循环的测试用例
n = 1
d. 找出点覆盖、边覆盖和主路径覆盖的所有TR（测试需求）
- 节点覆盖：[1,2,3,5,6,9,5,6,8,10,11,2,4,12,13,14]
边覆盖：[1,2,3,5,6,9,5,6,8,10,11,2,4,12,13,14]
[1,2,3,5,10,2,4,12,14]
主路径：[1,2,3,5,6,8,10,11]
[1,2,3,5,10,11]
[1,2,3,5,6,9]
[5,6,9,5]
[2,3,5,6,8,10,2]
[2,3,5,6,8,10,11,2]
[2,3,5,10,2]
[2,3,5,10,11,2]
[1,2,4,12,13,14]
[1,2,4,12,14]
[3,5,6,8,10,11,2,4,12,13,14]
[3,5,6,8,10,2,4,12,13,14]
[3,5,10,11,2,4,12,13,14]
[3,5,10,2,4,12,13,14]
[3,5,6,8,10,11,2,4,12,14]
[3,5,6,8,10,2,4,12,14]
[3,5,10,11,2,4,12,14]
[3,5,10,2,4,12,14]
[9,5,6,8,10,11,2,4,12,13,14]
[9,5,6,8,10,2,4,12,13,14]
[9,5,6,8,10,11,2,4,12,14]
[9,5,6,8,10,2,4,12,14]
主路径覆盖：
[0,1,2,3,5,6,8,10,11,2,4,12,13,14]
[0,1,2,3,5,6,8,10,11,2,4,12,14]
[0,1,2,3,5,6,8,10,2,4,12,13,14]
[0,1,2,3,5,6,8,10,2,4,12,14]
[0,1,2,3,5,6,9,5,6,8,10,11,2,4,12,13,14]
[0,1,2,3,5,6,9,5,6,8,10,2,4,12,13,14]
[0,1,2,3,5,6,9,5,6,8,10,11,2,4,12,14]
[0,1,2,3,5,6,9,5,6,8,10,2,4,12,14]
[0,1,2,3,5,10,11,2,4,12,13,14]
[0,1,2,3,5,10,2,4,12,13,14]
[0,1,2,3,5,10,11,2,4,12,14]
[0,1,2,3,5,10,2,4,12,14]