homework3

修改后的代码：

/**
     * Finds and prints n prime integers
     * Jeff Offutt, Spring 2003
     */
package prime;

public class Primes {

public 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[10];// 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-1; i++ ) {
//for each previous prime.
if(isDivisible(primes[i],curPrime)) {
//Found a divisor, curPrime is not prime.
isPrime = false;
break;
}
}
if(isPrime) {
// save it!
primes[numPrimes] = curPrime;
numPrimes++;

}
}// End while

// print all the primes out
for(int i = 0; i < numPrimes; i++) {
System.out.println("Prime: " + primes[i] );

}

}// End printPrimes.
boolean isDivisible(int i, int curPrime) {
if ( curPrime % i == 0 )
return true;
return false;
}

}

 

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

(b) 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.

假设MAXPRIMES=4时，t2数组越界，t1不会有错误

(c) 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.

n=1

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

node coverage:1,2,3,4,5,6,7,8,9,10,11,12,13,14,15

edge coverage:(1,2),(2,3),(2,4),(3,5),(4,12),(5,6),(6,8),(6,7),(7,11),(7,2),(8,9),(8,10),(9,7),(10,6),(11,2),(12,13),(12,15),(13,14),(14,12)

prime path coverage:

(1,2,4,12,15),(1,2,3,5,6,7,11),(1,2,3,5,6,8,9,7,11),(1,2,3,5,6,8,10),(1,2,4,12,13,14)

(2,3,5,6,7,2),(2,3,5,6,7,11,2)(2,3,5,6,8,9,7,2),(2,3,5,6,8,9,7,11,2),(2,3,5,6,8,10)

(3,5,6,7,11,2,4,12,15),(3,5,6,7,11,2,4,12,13,14)(3,5,6,7,2,4,12,15),(3,5,6,7,2,4,12,13,14),(3,5,6,8,9,7,2,4,12,15),(3,5,6,8,9,7,11,2,4,12,13,14),(3,5,6,8,9,7,2,4,12,15),(3,5,6,8,9,7,11,2,4,12,13,14)

(6,8,10,6)

(9,7,6,8,9)(9,7,6,8,10)

(10,6,8,10)

(12,13,14,12)

(14,12,13,14）

 

测试代码：

package prime;
import org.junit.Assert.*;  
import org.junit.Before;  
import org.junit.Test;  

public class testPrimes {
     private Primes pri;  
     
        @Before  
        public void setup(){  
            pri=new Primes();  
        }  
          
        @Test  
        public void testPrintPrimes(){  
            pri.printPrimes(10);  
      
        }  
}

运行结果