Question

请用C++编写 输出n行杨辉三角，每个数占4个位置，左对齐。

Answer 1

#include <iostream>
using namespace std;

void showTriangle(int n)
{
int **tri;
int i,j;
tri = new int*[n];
for(i = 0; i < n; i++)
{
tri[i] = new int [n]();
}
tri[0][0] = 1;
for(i = 1; i < n; i++)
{
tri[i][0] = 1;
tri[i][i] = 1;
for(j = 1; j < i; j++)
{
tri[i][j] = tri[i-1][j-1] + tri[i-1][j];
}
}
for(i = 0; i < n; i++)
{
for(j = 0; j < n-i-1; j++)
{
printf(" ");//改为两个空格
}
for(j = 0; j <= i; j++)
{
printf("%-4d",tri[i][j]);
}
printf("\n");
}
delete tri;
}

int main()
{
int n;
printf("输入行数:");
scanf("%d",&n);
printf("\n");
showTriangle(n);
}

输出的格式不符合的话可以稍微改下

Answer 2

#include<iostream>
using namespace std;

int main()
{

int i,j,n;

cout<<"input n: ";
cin>>n;
for(i=1;i<=n;i++)
{
for(j=1;j<=n-i;j++)
cout<<" ";
for(j=1;j<=i;j++)
cout<<j;
for(j=i-1;j>=1;j--)
cout<<j;
cout<<endl;
}

return 0;
}