# 输入一个正整数n（代表图形的行数），输出如样例形式的图形

输入：5

输出：

```json
        A
       ABA  
      ABCBA  
     ABCDCBA  
    ABCDEDCBA
```

以下程序实现了这一功能，请你填补空白处内容：

```cpp
#include <stdio.h>
#include <iostream>
using namespace std;
int main()
{
    int N;
    cin >> N;
    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j < N - i; j++)
            printf(" ");
        ______________________;
        printf("\n");
    }
    return 0;
}
```

## template

```cpp
#include <stdio.h>
#include <iostream>
using namespace std;
int main()
{
    int N;
    cin >> N;
    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j < N - i; j++)
            printf(" ");
        for (int j = 0; j < i; j++)
            printf("%c", (char)(j + 'A'));
        for (int j = i; j >= 0; j--)
            printf("%c", (char)(j + 'A'));
        printf("\n");
    }
    return 0;
}
```

## 答案

```cpp
for (int j = 0; j < i; j++)
	printf("%c", (char)(j + 'A'));
for (int j = i; j >= 0; j--)
	printf("%c", (char)(j + 'A'));
```

## 选项

### A

```cpp
for (int j = 0; j < i; j--)
	printf("%c", (char)(j + 'A'));
for (int j = i; j = 0; j++)
	printf("%c", (char)(j + 'A'));
```

### B

```cpp
for (int j = 0; j < i; j--)
	printf("%c", (char)(j + 'A'));
for (int j = i; j <= 0; j--)
	printf("%c", (char)(j + 'A'));
```

### C

```cpp
for (int j = 0; j < i; j--)
	printf("%c", (char)(j + 'A'));
for (int j = i; j <= 0; j--)
	printf("%c", (char)(j - 'A'));
```