C :

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

    return 0;
}

C++ :

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

Java :

import java.util.Scanner;
public class Main{
public static void main (String[] args){
	Scanner sc = new Scanner(System.in);
	int n = sc.nextInt();
	for(int i = 1; i <= n; i++) {
		for(int j = 1; j <= n - i + 1; j++) {
			System.out.print(j);
		}
		System.out.print('\n');
	}

}
}

Python :

n = int(input())
#行循环，i从第一行循环到n行
for i in range(1, n + 1):
#列循环，j从n-i+1开始到1
    for j in range(1,n - i + 2):
            print(j, end='')
    print()