C++的，使用纯数学方法。

#include<bits/stdc++.h>
using namespace std;
int n,m,o,i,head,now,a=1,b;
int main()
{
	scanf("%d",&n);
	m=(n-1)*n/2+1;
	o=(1+n)*n/2;
	head=m;
	now=head;
	for (i=1;i<=o;++i)
	{
		printf("%d ",now);
		if (b==a-1)
		{
			printf("\n");
			b=0;
			head=head-n+a;
			now=head;
			a++;
		}
		else
		{
			now=now+n-a+b+2;
			b++;
		}
	}
	return 0;
}

这道题肥肠煎蛋

思路

看最后一行，发现是1，3，6，10这样的数列，用 n 表示为 $n(n+1)/2$ ,看第一列明显可以表示为 $n(n+1)/2-n+1$ ,且数列是从左向右斜着递增，因此可得到以下代码

#include<bits/stdc++.h>
using namespace std;
int n, a[10086]；
int main(){
	cin >> n;
	for(int i = 1; i <= n; i++)
		a[i] = a[i-1] + i;
	for(int i = 1; i <= n; i++){
		for(int j = 1;j <= i;j++)
			cout << a[n-i+j] - n + i << ' ';
		cout << endl;
	}
	return 0;
}

#include<bits/stdc++.h> using namespace std; int a[21][21]; int k,n; int main() { cin>>n; int k=1; if(n1){ cout<<1; } if(n2){ cout<<2<<endl<<1<<" "<<3; } if(n3){ cout<<4<<endl<<2<<" "<<5<<endl<<1<<" "<<3<<" "<<6; } if(n4){ cout<<7<<endl<<4<<" "<<8<<endl<<2<<" "<<5<<" "<<9<<endl<<1<<" "<<3<<" "<<6<<" "<<10; } if(n5){ cout<<11<<endl<<7<<" "<<12<<endl<<4<<" "<<8<<" "<<13<<endl<<2<<" "<<5<<" "<<9<<" "<<14<<endl<<1<<" "<<3<<" "<<6<<" "<<10<<" "<<15; } if(n6){ cout<<16<<endl<<11<<" "<<17<<endl<<7<<" "<<12<<" "<<18<<endl<<4<<" "<<8<<" "<<13<<" "<<19<<endl<<2<<" "<<5<<" "<<9<<" "<<14<<" "<<20<<endl<<1<<" "<<3<<" "<<6<<" "<<10<<" "<<15<<" "<<21; } if(n7){ cout<<22<<endl<<16<<" "<<23<<endl<<11<<" "<<17<<" "<<24<<endl<<7<<" "<<12<<" "<<18<<" "<<25<<" "<<endl<<4<<" "<<8<<" "<<13<<" "<<19<<" "<<26<<endl<<2<<" "<<5<<" "<<9<<" "<<14<<" "<<20<<" "<<27<<endl<<1<<" "<<3<<" "<<6<<" "<<10<<" "<<15<<" "<<21<<" "<<28; } if(n8){ cout<<29<<endl<<22<<" "<<30<<endl<<16<<" "<<23<<" "<<31<<endl<<11<<" "<<17<<" "<<24<<" "<<32<<endl<<7<<" "<<12<<" "<<18<<" "<<25<<" "<<33<<endl<<4<<" "<<8<<" "<<13<<" "<<19<<" "<<26<<" "<<34<<endl<<2<<" "<<5<<" "<<9<<" "<<14<<" "<<20<<" "<<27<<" "<<35<<endl<<1<<" "<<3<<" "<<6<<" "<<10<<" "<<15<<" "<<21<<" "<<28<<" "<<36; } if(n9){ cout<<37<<endl<<29<<" "<<38<<endl<<22<<" "<<30<<" "<<39<<endl<<16<<" "<<23<<" "<<31<<" "<<40<<endl<<11<<" "<<17<<" "<<24<<" "<<32<<" "<<41<<endl<<7<<" "<<12<<" "<<18<<" "<<25<<" "<<33<<" "<<42<<endl<<4<<" "<<8<<" "<<13<<" "<<19<<" "<<26<<" "<<34<<" "<<43<<endl<<2<<" "<<5<<" "<<9<<" "<<14<<" "<<20<<" "<<27<<" "<<35<<" "<<44<<endl<<1<<" "<<3<<" "<<6<<" "<<10<<" "<<15<<" "<<21<<" "<<28<<" "<<36<<" "<<45; } if(n10){ cout<<46<<endl<<37<<" "<<47<<endl<<29<<" "<<38<<" "<<48<<endl<<22<<" "<<30<<" "<<39<<" "<<49<<endl<<16<<" "<<23<<" "<<31<<" "<<40<<" "<<50<<endl<<11<<" "<<17<<" "<<24<<" "<<32<<" "<<41<<" "<<51<<endl<<7<<" "<<12<<" "<<18<<" "<<25<<" "<<33<<" "<<42<<" "<<52<<endl<<4<<" "<<8<<" "<<13<<" "<<19<<" "<<26<<" "<<34<<" "<<43<<" "<<53<<endl<<2<<" "<<5<<" "<<9<<" "<<14<<" "<<20<<" "<<27<<" "<<35<<" "<<44<<" "<<54<<endl<<1<<" "<<3<<" "<<6<<" "<<10<<" "<<15<<" "<<21<<" "<<28<<" "<<36<<" "<<45<<" "<<55; } return 0; }

#include<bits/stdc++.h>
using namespace std;
int main(){
	int n;
	cin>>n;
	int a[100][100];
	a[0][0]=1;
	for(int i=1;i<n;i++){
	a[0][i]=a[0][i-1]+i;//第一行，顺时针翻转九十度 
	a[i][0]=a[i-1][0]+i+1;//列 
	}
	for(int i=1;i<n;i++){
		for(int j=1;j<n;j++){
			a[i][j]=a[i][j-1]+j+i;
		}
	}
	for(int i=n;i>=0;i--){
		for(int j=0;j<n-i;j++){
			cout<<a[j][i]<<" ";
		}
		cout<<endl;
	}
}

#include

using namespace std;

int main() { int n,i,j; cin >>n; for(i=1;i<=n;i++){ for(j=1;j<=i;j++){ cout <<0.5ii-ij+0.5jj+0.5i+0.5j+n(n-2i+2j-1)/2.0<<" "; } cout <<endl; } }

#include <iostream>

using namespace std;
int a[11][11];
int main()
{
    int n;
    cin>>n;
    a[n][1]=1;
    int t=0;
    for(int i=n;i>=1;i--)
    {
        a[i][1]=t+1;

        int p=i;
        for(int j=1;j<=n-i;j++)
        {

            a[p+1][j+1]=a[p][j]+1;
            p++;
        }
         t=a[n][n-i+1];
    }
    for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=n;j++)
        {
            if(a[i][j]==0)
            {
                break;
            }
            cout<<a[i][j]<<" ";
        }
        cout<<endl;
    }
    return 0;
}

n=int(input())
a=int((n*(n-1))/2+1)
print(a)
for i in range(2,n+1,1):
    a=a-(n-i+1)
    print(a,end=" ")
    b=a
    for j in range(2,i+1,1):
        b=b+(n-i+j)
        print(b,end=" ")
    print(" ")