C :

#include<stdio.h> 

int main(){ 
	int n,i,j,z;
	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 
		for(z=1;z <= 2 * i - 1;z++){
			printf("%c",i+64); 
		} 
		
		//负责换行
		printf("\n"); 
		
	}

	return 0; 
} 

C++ :

#include <iostream>
using namespace std;

int main(){ 
	int i,j,n;
	char c='A';
	cin>>n;
	for(i = 1;i <= n;i++){	
		for(j = 1;j <= n - i;j++){
			cout<<" ";
		} 		
		for(j = 1;j <= 2 * i - 1;j++){
			cout<<c;
		} 	
		cout<<endl;
		(char)(c++);
	} 	 
}

Python :

n=int(input())
i=65
while i<n+65:
    j=0
    k=0
    while k<n+64-i:
        print(" ",end="")
        k=k+1
    while j<(i-65)*2+1:
        print(chr(i),end="")
        j=j+1
    i=i+1
    print()