算法|杂项|问题11

在上述问题中，如果使数组A保留字符串“ abcde”，那么上述四个测试用例中的哪一个将成功暴露此过程中的缺陷?
(A)无
(B)仅2
(C)仅3和4
(D)仅4答案： (C)
解释：

#include 
#include 
  
void find_and_replace(char *A, char *oldc, char *newc) {
    for (int i = 0; i < 5; i++)
       for (int j = 0; j < 3; j++)
           if (A[i] == oldc[j]) A[i] = newc[j];
}
  
int main()
{
    char *oldc1 = "abc", *newc1 = "dab";
    char *oldc2 = "cde", *newc2 = "bcd";
    char *oldc3 = "bca", *newc3 = "cda";
    char *oldc4 = "abc", *newc4 = "bac";
  
    char test[] =  "abcde";
  
    printf("Test 2\n");
    printf("%s\n", test);
    find_and_replace(test, oldc2, newc2);
    printf ("%s\n", test);
  
    printf("\nTest 3\n");
    strcpy(test, "abcde");
    printf("%s\n", test);
    find_and_replace(test, oldc3, newc3);
    printf ("%s\n", test);
  
    printf("\nTest 4\n");
    strcpy(test, "abcde");
    printf("%s\n", test);
    find_and_replace(test, oldc4, newc4);
    printf ("%s\n", test);
}

输出：

Test 2
abcde
abbcd

Test 3
abcde
addde

Test 4
abcde
aacde

这个问题的测验