Question

下記の砂時計形★タワーを印字する(△はスペース)
Example:

input_5

        ★★★★★
        △★★★△     
        △△★△△
        △★★★△
        ★★★★★

input_3

        ★★★     
        △★△
        ★★★

input_9

        ★★★★★★★★★    
        △★★★★★★★△
        △△★★★★★△△
        △△△★★★△△△    
        △△△△★△△△△
        △△△★★★△△△
        △△★★★★★△△
        △★★★★★★★△
        ★★★★★★★★★

Solution

solution.cpp

#include <iostream>
#define SKIP 2
using namespace std;

void printStar( int stars ){
    
    for( int i = 0; i < stars; i++ )
        cout << "*";
}

void printSpace( int spaces ){
    
    for( int i = 0; i < spaces; i++ )
        cout << " ";
}

int main(void){

    int times;
    cout << "Input an ODD number to print star hourglass:\n";
    cin >> times;

    if( 0 == times % 2 ){
        cout << "Please input an ODD number!" << endl;
        return 0;
    }

    int stars, spaces, revPos;
    
    // reverse point is the most stars of lines
    revPos = times / 2;
    
    for( int i = 0; i < times; i++ ){

        // count stars and spaces in this line
        if( i <= revPos ){
            stars = times - i * SKIP;
            spaces = times - stars;
        }else{
            stars = times - ( ( times - ( i + 1 ) ) * SKIP );
            spaces = times - stars;
        }
        
        // stars always start from the center, insert spaces in the front and tail of stars
        printSpace(spaces/2);
        printStar(stars);
        printSpace(spaces/2); //this line can be commented out
        
        // change line
        cout << endl;
    }
}