每日13

四则运算记录错题的函数

利用了数组，和题目数组一一对应，0为没有错，非零代表错了几次

public String[] Mistakes(String str[], int a[], int b[], int j3) {
int total = 0;
String c[] = new String[j3];
for (int i = 0; i < j3; i++) {
if (a[i] != b[i]) {
c[total] = str[i];
total++;
}
}
if (total == 0) {
return null;
} else {
String d[] = new String[total];
for (int i = 0; i < total; i++) {
d[i] = c[i];
}
return d;
}
}