```c
int main() {
int a[20], * p[4], j, k = 0;
for (j = 0; j < 20; j++)
a[j] = j;
for (j = 0; j < 4; j++)
p[j] = &a[j * (j + 1)];
for (j = 0; j < 4; j++)
k += p[j][j];
printf("% d", k);
return 0;
}
//1.p不是一维的吗?怎么会有p[j][j]?
//2.如果p是二维的,那么p是几行几列
//3.结果是多少,最后
```