杨辉三角

#include <iostream>using namespace std;int fac(int x);int main(){    int a[30][30],n;    int i,j;    cin>>n;    for(i=0; i<n; i++)    {        a[i][0]=1;        a[i][i]=1;    }    for(i=2; i<n; i++)        for(j=1; j<i; j++)        {            a[i][j]=fac(i)/(fac(j)*fac(i-j));        }    for(i=0; i<n; i++)    {        for(j=0; j<i; j++)        {            cout<<a[i][j]<<" ";        }        cout<<a[i][i]<<endl;    }    return 0;}int fac(int x){    int s;    if(x==1||x==0)        s=x;    else    {        s=fac(x-1)*x;        return s;    }}<img src="http://img.blog.csdn.net/20141209171346833?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvemh5NzE3NDUyMzgz/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center" alt="" />