C语言解答

#include<stdio.h> 
int main()
{
	int a[101],b,n,m,tag;
	while(scanf("%d",&n)!=EOF)
	{
		for(int i=n;i>0;i--)
		{
			printf("%*s",n-i,"");
			for(int k=i*2-1;k>0;k--)
				printf("*");
			printf("\n");
			
		} 

	}
	return 0;
}

C++解答

#include <iostream>
using namespace std;
int main()
{
	int n,i,j;
	cin>>n;
	for(i=1;i<=n;i++)
	{
		for(j=1;j<i;j++)
		{
			cout<<' ';
		}
		for(j=1;j<=2*(n-i)+1;j++)
		{
			cout<<'*';
		}
		cout<<endl;
	}
	return 0;
}

Java解答

import java.util.Scanner;
public class Main{
    public static void main(String[] args){
        Scanner in=new Scanner(System.in);
        while(in.hasNext()){
            int n=in.nextInt();
            int step=n;
            for(int j=0;j<n;j++){
                for(int k=0;k<j;k++){
                    System.out.print(" ");
                }
                for(int i=1;i<=2*step-1;i++){
                    System.out.print("*");
                }
                step--;
                System.out.println();
            }
        }
    }
}