程序代码：

//打印菱形

import java.util.*;

public class LingXing {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        int level = s.nextInt();
        
        print(level);
            
    }    
    
    public static void print(int level) {
        int t = (level + 1) / 2;
        int i, j;
        
        for(i = 1; i<=t; i++) { //打印上半部分
            for(j = 1; j<=t-i; j++) {
                System.out.print(" ");    
            }    
            
            for(j = 1; j<=2*i-1; j++) {
                System.out.print("*");    
            }
            
            System.out.println();
        }    
        
        for(i = 1; i<t; i++) { //打印下半部分
            for(j = 1; j<=i; j++) {
                System.out.print(" ");    
            }    
            
            for(j = (t-i)*2-1; j>=1; j--) {
                System.out.print("*");    
            }
            
            System.out.println();
        }
    }
}

程序代码：

#include <stdio.h>
#define MAXSTAR "*********************"
void print( int level, int max_len, int num );

int main(int argc, char *argv[])
{
    int level = 0;
    int max_len = 0;
    
    while(1)
    {
        printf( "please input level(it must be a prime num): " );
        scanf( "%d", &level );
        if( level % 2 == 1 )
        {
            max_len = level;
            break;
        }
    }
    print( (level + 1) / 2 , max_len, 1 );
    return 0;
}

void print( int level, int max_len, int num )
{    
    int space_len = max_len - level + 1;
    
    if( --level )
    {
        printf( "%*.*s\n", space_len , 2 * num - 1, MAXSTAR );
        print( level, max_len, num+1 );
    } 
    printf( "%*.*s\n", space_len , 2 * num - 1, MAXSTAR );
}