倒三角形 (triangle)

输入正整数n<=20，输出一个n层的倒三角形。

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

随手附上正三角形

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