Python3:

def staircase(n):
    for x in range(1, n + 1):
        print(("#"*x).rjust(n))

In C++ we can use string constructor and solve this

void staircase(int n) {
    for( int i = 1; i<=n; i++)
    {
        cout<<string(n-i, ' ')<<string(i, '#')<<endl;
    }
}

C++

void staircase(int n) {
string hash = "#";
for (int i = 0; i < n; i++, hash += "#") {
    for (int j = n-i; j > 1; j--) {
        cout << " ";
    }
    cout << hash << endl;
    }
}

public static void staircase(int n) {
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            if (i+j >= n-1) {
                System.out.print("#");
            } else {
                System.out.print(" ");
            }
        }
        System.out.println("");
    }
}

JAVA CODE: ` public static void staircase(int n) {

    int padding = 0;
    int elem = 0;
    for(int i = 1; i <= n; i++) {
        padding = n - i;
        elem = n - padding;
        if(padding > 0) System.out.format("%" + padding + "s", "");
        do {
            System.out.print("#");
            elem--;
        } while(elem > 0);
        System.out.println();
    }

}

`