题目：课本49页7题a）b）c）d）
解答如下：
a）PrintPrimes（）方法的控制流图如下：
b）例如MAXPRIMES=4时，t2=(n=5)会出现数组越界的问题。
c）n=1时会出现。
d）节点覆盖：{0,1,2,3,4,5,6,7,8,9,10,11,12,13}
边覆盖：{（0，1），（1,2），（1,10），（2,3），（3,4），（3,7），（4,5），（4,6），（5,7），（6,3），（7,8），（7,9），（8,9），（9,1），（10,11）， （11,12），（11,13），（12,11）}
主路径覆盖：{[6,3,4,5,7,8,9,1,10,11,13][6,3,4,5,7,8,9,1,10,11,12][2,3,4,5,7,8,9,1,10,11,12,13][2,3,4,5,7,8,9,1,10,11,,12][6,3,4,5,7,9,1,10,11,13][6,3,4,5,7,9,1,10,11,12][4,6,3,7,8,9,1,10,11,13][4,6,3,7,8,9,1,10,11,12][3,4,5,7,8,9,1,10,11,13][3,4,5,7,8,9,1,10,11,12][2,3,4,5,7,9,1,10,11,13][2,3,4,5,7,9,1,10,11,129,1,2,3,4,5,7,8,9][8,9,1,2,3,4,5,7,8][7,8,9,1,2,3,4,5,7][5,7,8,9,1,2,3,4,5][4,6,3,7,9,1,10,11,12][4,5,7,8,9,1,2,3,4][3,4,5,7,8,9,1,2,3][2,3,7,8,9,1,10,11,13][2,3,7,8,9,1,10,11,12][2,3,4,5,7,8,9,1,2][1,2,3,4,5,7,8,9,1][9,1,2,3,4,5,7,9][7,9,1,2,3,4,5,7][6,3,7,9,1,10,11,13][6,3,7,9,1,10,11,12][5,7,9,1,2,3,4,5][4,5,7,9,1,2,3,4][2,3,7,9,1,10,11,13][2,3,7,9,1,10,11,12][2,3,4,5,7,9,1,2][1,2,3,4,5,7,9,1][9,1,2,3,7,8,9][7,8,9,1,2,3,7][3,7,8,9,1,2,3][2,3,7,8,9,1,2][1,2,3,7,8,9,1][9,1,2,3,7,9][2,3,7,9,1,2][1,2,3,7,9,1][6,3,4,6][4,6,3,4][3,4,6,3][12,11,12][11,12,11]}