Alphabet Rangoli

#include <bits/stdc++.h>
using namespace std;

int linesize;
int n;

void rep(char c, int t)
{
    for (int i = 0; i < t; ++i)
        printf("%c", c);
}

void printline(int i)
{
    int mid = 4*i-3; // size of middle portion c-b-a-b-c
    int lr = (linesize-mid)/2;
    rep('-', lr);
    for (int j = i-1; j >= 1; --j)
        printf("%c-", ('a'+n-i)+j);
    printf("%c", 'a'+n-i);
    for (int j = 1; j <= i-1; ++j)
        printf("-%c", ('a'+n-i)+j);
    rep('-', lr);
    printf("\n");
}

int main()
{
    scanf("%d", &n);
    linesize = 4*n-3;

    for (int i = 1; i <= n; ++i)
        printline(i);
    for (int i = n-1; i >= 1; --i)
        printline(i);

    return 0;
}