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("*");
    }
    printf("\n");
}
return 0;

}

C++ :

#include <iostream>
using namespace std;
int main(){
	int a;
	int pos=1;
	cin>>a;
    while(pos<=a){
	    for(int i=1;i<=pos;i++)
		    cout<<'*';
	    cout<<endl;
	    pos++;
	}
	return 0;
}

Java :

public class Main 
    {
            public static void main(String[] args)
            {
              java.util.Scanner input = new java.util.Scanner(System.in);
              int n = input.nextInt();
              for(int n1=1;n1<=n;n1++) {
                for(int i=0;i<n1;i++){
                  System.out.print("*");
                }
               System.out.print("\n");
              }
            }
}

Python :

# coding=utf-8
a=int(input())
i=1
while(i<=a):
    for j in range(i):
        print("*", end='')
    print()
    i=i+1