C :

#include<stdio.h>
int main()
{
	int n,i,j;
	scanf("%d",&n);
	int a[n][n];
	for(i=0;i<n;i++){
		a[i][0]=n;
		for(j=1;j<=i;j++){
			a[i][j]=a[i][j-1]-1;
		}
		for(j=i+1;j<n;j++){
			a[i][j]=a[i][j-1];
		}
     
	}
	for(i=0;i<n;i++){
		for(j=0;j<n;j++){
			printf("%3d",a[i][j]) ;
		}
		printf("\n");
	}
return 0;
}

C++ :

#include <bits/stdc++.h>

using namespace std;

int main(){
	 int n,a[423][423],i,j;
	 cin>>n;
	 for(i=1;i<=n;i++){
	 	for(j=1;j<=n;j++){
	 		if(i<j){
	 			a[i][j]=n-i+1;
			 }
			 else{
			 	a[i][j]=n-j+1;
			 }
		 }
	 }
	 for(i=1;i<=n;i++){
	 	for(j=1;j<=n;j++){
	 		cout<<setw(3)<<a[i][j];
		 }
		 cout<<endl;
	 }
} 

Python :

n = int(input())
a = [[0 for j in range(n)] for i in range(n)]

for i in range(n):
    # 先定好第一列数字
    a[i][0] = n
    for j in range(1, i + 1):
        a[i][j] = a[i][j - 1] - 1
    for j in range(i + 1, n):
        a[i][j] = a[i][j - 1]

for i in range(n):
    for j in range(n):
        print('%3d' % a[i][j], end='')
    print()