CareerCup

Java Code & Tested

public class Numbers {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		Numbers numbers=new Numbers();
		
		numbers.printNumbers(3);

                //numbers.printNumbers(5);
	}
	
	
    public void printNumbers(int n){
    	int[] a={1,2,3,4,5,6,7,8,9};
    	
    	subPrint("",0,n,a);
    	
    }
    
    private void subPrint(String preFix,int startIndex,int numberCount,int[] a){
    	
    	for(int i=startIndex;i<a.length;i++){
    		
    		int digit=a[i];
    		
    		if(numberCount==1){
    			System.out.println(preFix+digit);
    		}else{
    			subPrint(preFix+digit,digit,numberCount-1,a);
    		}
    		
    	}
    }
}

void printNumbers(int n, int op)
{
	int lastDigitUsed = (op/power(10,n))%10;
	for(int i=lastDigitUsed+1; i<10;i++)
	{
		int temp = op+i*(power(10, n-1));
		if(n == 1)
			printf("%d", temp);
		else 
			printNumbers(n-1, temp);
	}
			
}

#include<stdio.h>
void printNumbers(int);
int power(int , int);
int main()
{
int n;
scanf("%d",&n);
printNumbers(n);
return 0;
}
void printNumbers(int n)
{
int i;
int in,fn;
in=power(10,n-1)+1;
fn=power(10,n)-1;
for(i=in;i<fn;i++)
{ int flag=1;
int j=i;
while(j>9)
{
int temp2 =j%10;
int temp1=(j/10)%10;
if(temp1<temp2)
{
j=j/10;
}
else
{
flag=0;
j=0;
}
}
if(flag==1)
{
printf("%d,",i);
}
}
}
int power(int num, int p)
{
int j;
int k=num;
for(j=1;j<p;j++)
{
num*=k;
}
return (num);
}

/*
Given n. Generate all numbers with number of digits equal to n, such that the digit to the right is greater than the left digit (ai+1 > ai). E.g. if n=3 (123,124,125,……129,234,…..789)
*/

#include <iostream>
#include <cmath>

static bool is_valid_number(int num, int digits) {
	int base = std::pow(10, digits - 1);
	int arr[digits];


	bool ret = true;
	int saved = -1;

	for(int i = 0; i < digits; ++i) {
		int res = num / base;
		//std::cout << "res: " << res << std::endl;
		num = num - (base * res);
		base /= 10;
		arr[i] = res;

		if(saved == -1) {
			saved = res;
			continue;
		}
		
		if(res <= saved) {
			ret = false;
			break;
		} else {
			saved = res;
			continue;
		}
	}

	return ret;
}

int main() {
	static const int digits = 3;
	
	int initial = std::pow(10, (digits - 1));
	int final = std::pow(10, digits); 
	
	while(initial < final) {
		if(is_valid_number(initial, digits))
			std::cout << initial << std::endl;

		++initial;
	}

	return 0; 
}

Solution in C++:

#include <cstdio>

int printNumber(char num[], int next, int remain)
{
    if(remain == 0){
        puts(num);
        return 1;
    }

    char smallest = next == 0 ? '1' : num[next-1]+1;
    char largest = '9' - remain + 1;
    int sum = 0;
    for(--remain; smallest <= largest; ++smallest){
        num[next] = smallest;
        sum += printNumber(num, next+1, remain);
    }
    return sum;
}
int printNumber(int n)
{
    if(n > 9) return 0;
    if(n == 9){
        puts("123456789");
        return 1;
    }
    char num[9];
    num[n] = '\0';
    return printNumber(num, 0, n);
}

int main()
{
    printf("%d in total\n", printNumber(4));

    return 0;
}

void printnum(int n, string s, int last){
if (n == 0) cout << s << " ";
for (int i = 1; i < last; i++){
printnum(n - 1, to_string(i) + s, i);
}
return;
}

#include<iostream>
using namespace std;
void printArr(int arr[],int size)
{
for(int i=0;i<size;i++)
{
cout<<arr[i]<<" ";
}
cout<<endl;
}
void genUtil(int str[],int n,int pos,int prev)
{
if(9-prev<(n-pos-1))return;
if(pos==n)
{
printArr(str,n);
return;
}
for(int i=prev+1;i<=9;i++)
{
str[pos]=i;
genUtil(str,n,pos+1,i);
}
}
void generateNums(int n)
{
int str[n];
genUtil(str,n,0,0);
}
int main()
{
int n=4;
generateNums(n);
return 0;
}

//Solution in C++

#include <iostream>
#include <math.h>
using namespace std;


void printSeq(int n, int sum, int lastDigit)
{
int res = 0;
if(n==0)
{
cout<<sum<<"\n";
}
else
{
for(int i = lastDigit+1; i <10; i++)
{
res = i * pow(10,n-1)+sum;
printSeq(n-1,res,i);
}

}
}


int main() {
// your code goes here
printSeq(3,0,0);
return 0;
}

import math
def function(n):
    count=0
    while(n>0):
        f=n%10
        g=(n%100)/10
        if(f>g):
            count=count+1
        n=n//10
    return (count)
a=int(input("Enter the no of digits: "))
for i in range(pow(10,a-1),pow(10,a)):
    if(function(i)==a):
       print(i)

import math
def function(n):
    count=0
    while(n>0):
        f=n%10
        g=(n%100)/10
        if(f>g):
            count=count+1
        n=n//10
    return (count)
a=int(input("Enter the no of digits: "))
for i in range(pow(10,a-1),pow(10,a)):
    if(function(i)==a):
       print(i)

static void getnum(String result, String number, int size){
if (size == 0)
System.out.println(result);
else {
for (int i = 0; i < number.length(); i++){
if (result.length() >= 1)
{
if (Integer.parseInt(result.charAt(result.length() - 1) + "") < Integer.parseInt(number.charAt(i)+""))
printnum(result + number.charAt(i), number, size - 1);
}
else
getnum(result + number.charAt(i), number, size - 1);
}
}
return;
}

static void getnum(String result, String number, int size){
if (size == 0)
System.out.println(result);
else {
for (int i = 0; i < number.length(); i++){
if (result.length() >= 1)
{
if (Integer.parseInt(result.charAt(result.length() - 1) + "") < Integer.parseInt(number.charAt(i)+""))
getnum(result + number.charAt(i), number, size - 1);
}
else
getnum(result + number.charAt(i), number, size - 1);
}
}
return;
}

n = 3;
st = 10^n - 1;
i = 1;
while st > 10^(n-1)
    myStr1 = sprintf('%.0f',st) - '0';
    myStr2 = [myStr1(2:1:n),0];
    if sum((myStr1(1:1:(n-1)) - myStr2(1:1:(n-1))) < 0) == n-1
        myArray(i) = st;
        i=i+1;
    end
    st=st-1;
end
myArray

public class Program
    {
        public void print_it(int init, int dig) {
            int num = init;
            while (init != 0) {

                if (init % 10 <= (init / 10) % 10) break;
                init = init / 10;
            }
            if (init == 0) Console.WriteLine(num);
        }
        public static void Main(string[] args)
        {
            Program a = new Program();
            int initial = (int)Math.Pow(10, 2);
            int final = (int)Math.Pow(10, 3);
            while (initial < final) {
                a.print_it(initial, 3);
                initial++;
            }
        }
    }

public class Program
    {
        public void print_it(int init, int dig) {
            int num = init;
            while (init != 0) {

                if (init % 10 <= (init / 10) % 10) break;
                init = init / 10;
            }
            if (init == 0) Console.WriteLine(num);
        }
        public static void Main(string[] args)
        {
            Program a = new Program();
            int initial = (int)Math.Pow(10, 2);
            int final = (int)Math.Pow(10, 3);
            while (initial < final) {
                a.print_it(initial, 3);
                initial++;
            }
        }
    }

static void rightGreaterleft(int n)
{
int low=(int) Math.pow(10, n-1);
int high=(int) (Math.pow(10, n)-1);
System.out.println(low+" "+high);
for(int i=low;i<=high;i++)
{
printNumbers(i,n);


}
}
static void printNumbers(int num,int digits)
{
String str=Integer.toString(num);
int i=0;
int flag=0;
while(i<digits-1)
{
if(str.charAt(i)>=str.charAt(i+1))
{
flag=1;
break;
}
i++;
}
if(flag==0)
System.out.println(str);
}

static void rightGreaterleft(int n)
{
int low=(int) Math.pow(10, n-1);
int high=(int) (Math.pow(10, n)-1);
System.out.println(low+" "+high);
for(int i=low;i<=high;i++)
{
printNumbers(i,n);


}
}
static void printNumbers(int num,int digits)
{
String str=Integer.toString(num);
int i=0;
int flag=0;
while(i<digits-1)
{
if(str.charAt(i)>=str.charAt(i+1))
{
flag=1;
break;
}
i++;
}
if(flag==0)
System.out.println(str);
}

#include <iostream>
using namespace std;
void printArr(int arr[],int n)
{
	for(int i=0;i<n;i++)cout<<arr[i]<<" ";
	cout<<endl;
}
void genUtil(int arr[],int n,int pos)
{
	if(arr[pos-1]==9 && pos!=n)return;
	if(pos==n)printArr(arr,n);
	for(int i=arr[pos-1]+1;i<10;i++)
	{
		arr[pos]=i;
		genUtil(arr,n,pos+1);
	}
}
void generate(int n)
{
	if(n==0)return;
	int arr[n];
	for(int i=1;i<10;i++){
		arr[0]=i;
		genUtil(arr,n,1);
	}
}
int main() {
	generate(3);
	return 0;
}

public static void numbers(char [] sol, char current, int nivel, int fin){
		if(nivel > fin-1 ){
			System.out.println(sol);
		}
		else{
			for(char i=(char) (current+1); i<='9'; i++){
				sol[nivel]= i;
				numbers(sol, i, nivel+1, fin);
			}
		}
	}

	public static void main(String[] args) {
		
		Scanner scan = new Scanner(System.in);
		int fin = scan.nextInt();
		char [] sol = new char[fin];
		
		numbers(sol, '0', 0, fin);
	}

#include<stdio.h>
#include<stdlib.h>
void print(int *a, int size)
{
int i;
for(i=1;i<size;i++)
printf("%d",a[i]);
printf("\n");
}
void allnumprint(int *a,int i,int size)
{
if(i>=size-1)
print(a,size);
else
{
a[i+1]=a[i]+1;
while(i<size-1&&a[i+1]<=9)
{
allnumprint(a,i+1,size);
a[i+1]+=1;
}
}
}
int main()
{
int i,n,*a;
printf("Enter number of digits:");
scanf("%d",&n);
n+=1;
a=(int *)malloc(n*sizeof(int));
for(i=0;i<n;i++)
a[i]=0;
allnumprint(a,0,n);

}

int n = 4;
		double startNo = 0;
		int no = 1;
		for (int i = n - 1; i >= 0; i--) {
			startNo = no * (Math.pow(10, i)) + startNo;
			no++;
		}
		
		//System.out.println(startNo);
		int start = (int) startNo;
		//System.out.println(start);
		
		int base = 10;
		double maxNo = 0;
		int maxStart = 10 - n;
		int pow = n - 1;
		for (int i = maxStart ; i < 10; i++) {
			maxNo = i * (Math.pow(10, pow)) + maxNo;
			pow--;
		}
		System.out.println("maxNo " + maxNo);
		while (start <= maxNo) {
			int rem = start % base;
			int quo = start / base;
			for (int next = rem; next <10; next++) {
				System.out.println((quo*base) + next);
			}
			//base = base * 10;
			double nextStart = 0;
			for (int i = n - 1 ; i >= 0; i--) {
				nextStart = 1 * (Math.pow(10, i)) + nextStart;
			}
			//System.out.println(nextStart + "--------------");
			start = start + (int) nextStart;
			
		}

Answer would be F(number , 0,0).

F(digits_left, number,  min_dig) {
If(digits_left==0)print (number) ;
For(int i=min_dig+1;i<=10-digits_left;i++){
F(digits_left -1,number*10+i, i);
} 
}

public class ProgressiveDigits {
	public static void main(String[] args){
		int n = 4;
		int digit = 0;
		int lower_bound = (int) Math.pow(10, n-1);
		int upper_bound = (int) Math.pow(10, n);
		for(int result = lower_bound; result < upper_bound; result++){
			if(checkProgress(n, result, digit)){
				System.out.println(result);
			}
		}		
	}
	
	static boolean checkProgress(int n, int result, int digit){			
		while(digit < n ){
			if((result/(int) Math.pow(10, digit))%10 > (result/(int) Math.pow(10, digit+1))%10){
				digit++;				
			}else{
				return false;
			}			
		}
		return true;
	}
	
}

Following is my code in java:

public static void main(String args[])
	{
		calculate(0,3);
	}
	private static void calculate(int i,int len)
	{ int j;
		if(len==0)
		{
			System.out.println(i);
			i=i/10;
			return;
		}
		if(i%10==0)
		{for(j=1;j<=(9-len+1);j++)
		{
			i=j;
			calculate(i,len-1);
			i=i/10;
		}
		}
		else
		{
			for(j=((i%10)+1);j<10;j++)
			{
				i=i*10+j;
				calculate(i,len-1);
				i=i/10;
			}
		}
			
		
	}
}

import java.util.ArrayList;
import java.util.Scanner;

public class orderednos {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		ArrayList<Integer> al = new ArrayList<Integer>();
		Scanner in = new Scanner(System.in);
		int num = in.nextInt();
		
		int start = (int) Math.pow(10, num-1);
		int end = (int) Math.pow(10, num);
		
		for(int i = start; i < end-1; i++)
		{
			
			if(i/Math.pow(10, num) > (i%10))
			{
				continue;
			}
			else
			{
				int temp=i;
				int count=0;
				for(int k=0; k <= num; k++ )
				{
					int remain = temp%10;
					al.add(remain);
					temp = temp/10;
				}
				int max = al.get(0);				
				for(int m=1; m < al.size();m++)
				{
					if(max > al.get(m))
					{
						max= al.get(m);
						count++;
					}
				}
				if(count == al.size()-1)
				{
					System.out.println(i);
				}
				al.clear();				
			}
		}
	}
}

#include<iostream>
using namespace std;
void fn(int num, int dig, int len)
{

    int i, no;
    if(len == 0)
    {
        cout<<num<<"\n";
        return;
    }
    for(i = dig; i<=9; i++)
    {
        no = (num*10)+i;
        fn(no, i+1, len-1);
    }
}
main()
{
    fn(0, 1, 3);
}

I use DFS to solve this problem. compiled!

public class Numbers {
	public static void main(String[] args){
		int[] num = {1, 2, 3, 4, 5, 6, 7, 8, 9};
		StringBuilder sb = new StringBuilder();
		helper(num, 0, sb, 3);
	}
	public static void helper(int[] num, int pos, StringBuilder sb, int size){
		if (sb.length() == size) {
			System.out.println(sb.toString());
		}
		for (int i = pos; i < num.length; i++) {
			sb.append(num[i]);
			helper(num, i + 1, sb, size);
			sb.deleteCharAt(sb.length() - 1);
		}
	}

}

void reur_call(int start, int end, int stage, int num)
{
	if(stage == 0)
	{
		cout << num << endl;
		return;
	}
	stage = stage -1;
	for(int i = start; i<= end; i++)
	{
		reur_call((i+1), (end+1), (stage), (num*10+i));
	}
}

void call()
{
	int input = 4;
	int start = 1;
	int end = 10 - input;
	reur_call(start, end, input, 0);
}

{public class WellOrderedNumber
{
public void order(String str, int leng)
{
if(leng==0)
{
System.out.println(str);
}


char c;
if(str.length()==0)
{
c = '1';
}
else
{
c = (char)(str.charAt(str.length()-1)+1);
}
for(;c<'9';c++)
{
order(str+c,leng-1);
}

}

public static void main(String args[])
{
WellOrderedNumber w = new WellOrderedNumber();
w.order("", 3);
}
}

public class mySolution {

	
	public static void perm(String num, int j){
		
		if(num.length() == 3){
			
			System.out.println(num);
			return;
		}
		
		for(int i = j; i<10; i++){
			
			perm(num + String.valueOf(i),i+1);
		}
	}
	
	public static void main(String[] args) {
		
	
		perm("",1);

	}

}

Basic recursive practice. Just don't forget 0 when n == 1.
Playable code:

ideone.com/OYUBa3

vector<int> helper(int n, int pre) {
	if (n == 0) return vector<int>{pre};

	vector<int> ret;
	for (int i = pre % 10 + 1; i <= 9; ++i) {
		auto tmp = helper(n - 1, pre * 10 + i);
		ret.insert(ret.end(), tmp.begin(), tmp.end());
	}
	return ret;
}

vector<int> gen(int n) {
	if (n <= 0) return vector<int>();
	auto ret = helper(n, 0);
	if (n == 1) ret.push_back(0);

	return ret;
}

written in python 3

def q2(n):
    num = ""; unum = ""; ans = []
    for i in range(1, n + 1): num = num + str(i)
    for i in range(10-n, 10): unum = unum + str(i)
    num = int(num); unum = int(unum)
    
    for i in range(num - 1, unum + 1):
        d = list(map(int, str(i)))
        for j in range(len(d)-1):
            if d[j] < d[j + 1]:
                if j == n - 2: ans.append(i)
            else:
                break
    return ans