C :

#include<stdio.h>
int main()
{
    int n,i,j;
    scanf("%d",&n);
   
    for(i=1;i<=n;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;
    cin>>n;
    for(int i=1;i<=n;i++){ 
        for(int 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 m = 1; m <= i; m ++) {
				System.out.print(m);

		}
	
		System.out.print('\n');
	}
	
	
	
}
}

Python :

n = int(input())
for i in range(1, n + 1):
    for j in range(1, i + 1):
        print(j, end='')
    print()