C :

#include<stdio.h> 

int main(){ 
	int n,i,j,z,m;
	scanf("%d",&n);
	//负责行 
	for(i = 1;i <= n;i++){
		//负责空格
		for(j = 1;j <= n - i;j++){
			printf(" "); 
		} 
		//负责打印大写的字母左边
		for(m = i - 1;m >= 1;m--){
			printf("%c",65+m); 
		} 
		//负责中间 
		printf("%c",65) ;
		//负责右边 
		for(z=1;z <= i - 1;z++){
			printf("%c",65+z); 
		} 
	
		//负责换行
		printf("\n"); 
		
	}

	return 0; 
} 

C++ :

#include<iostream>
using namespace std;
int main(){
	int i,j,n;
	cin>>n;
	char c;
	for(i=1;i<=n;i++){
		for(j=1;j<=n-i;j++){
			cout<<" ";
		}
		for(j=i;j>=2;j--){
			c=j+64;	
			cout<<c;
		}
		for(j=1;j<=i;j++){
			c=j+64;
			cout<<c;
		}
		cout<<endl;
	}
}

Python :

import math;
n = int(input())
for i in range(1,n+1):
     for j in range(1,n-i+1):
          print(' ',end='')
     for k in range(1,2*i):
          print(chr(int(math.fabs(k-i))+65),end='')
     print()