Aryan and his friends are very fond of the pattern. They want to make the Reverse N-Number Crown for a given integer' N'.
Given 'N', print the corresponding pattern.
Example:
Input: ‘N’ = 3
Output:
1 1
1 2 2 1
1 2 3 3 2 1
The first line of the input contains an integer 'N’.
Print the pattern as specified in the problem statement.
1 <= N <= 20
Time Limit: 1 sec
3
1 1
1 2 2 1
1 2 3 3 2 1
4
1 1
1 2 2 1
1 2 3 3 2 1
1 2 3 4 4 3 2 1
7
1 1
1 2 2 1
1 2 3 3 2 1
1 2 3 4 4 3 2 1
1 2 3 4 5 5 4 3 2 1
1 2 3 4 5 6 6 5 4 3 2 1
1 2 3 4 5 6 7 7 6 5 4 3 2 1
Iterate to all the cells.
Approach:
The solution is iterating on the pattern and printing every cell with the required number.
The steps are as follows :
Function void numberCrown(int ‘N’)
O( N * N ), Where N is the given input integer.
Two nested loops are running N * (2 * N) times so that time complexity would be the order of N * N.
Hence the time complexity is O( N * N ).
O(1).
Since we are using constant extra space.
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Interview problems
Using Java
public class Solution {
public static void numberCrown(int n) {
// Write your code here.
int space= 2*(n-1);
for(int i=1;i<=n;i++){
for(int j=1;j<=i;j++){
System.out.print(j+" ");
}
for(int j=1;j<=space;j++){
System.out.print(" ");
}
for(int j=i;j>=1;j--){
System.out.print(j+" ");
}
System.out.println();
space -=2;
}
}
}
Interview problems
Using c++
void numberCrown(int n) {
// Write your code here.
int space= 2*(n-1);
for(int i=1;i<=n;i++){
for(int j=1;j<=i;j++){
cout<< j<<" ";
}
for(int j=1;j<=space;j++){
cout<<" ";
}
for(int j=i;j>=1;j--){
cout<< j<<" ";
}
cout<<endl;
space -=2;
}
}
Step
Outer loop for the number of rows.
for printing numbers in each row
for printing spaces in each row
for printing numbers in each row
As soon as the numbers for each iteration are printed, we move to the
next row and give a line break otherwise all numbers
would get printed in 1 line.
After each iteration nos. increases by 2, thus
spaces will decrease by 2.
Interview problems
Simple Python program
def numberCrown(n: int) -> None:
# Write your solution here.
for i in range(1, n+1):
for j in range(1, i+1):
print(j, end=' ')
for space in range(1, 2*(n-i)):
print(end=' ')
for j in range(i, 0, -1):
print(j, end=' ')
print()
passInterview problems
Easy Python Solution
space=2*(n-1)
for i in range(1,n+1):
for j in range(1,i+1):
print(j,end=" ")
for j in range(1,space+1):
print(" ",end=" ")
for j in range(i,0,-1):
print(j,end=" ")
print()
Interview problems
Using Math & String
when we see into the problem , we can observe that 1. the input n
2. the number of rows , relate the input to the number of the rows. 3. then try to figure the number of columns , and figure a relation to the rows.
4. find if any pattern can be drawn between the rows and columns
def numberCrown(n: int) -> None:
for i in range(1,n+1):
print(*range(1,i+1),end=" ")
print(" "*2*((2*n)-(2*i+1)),end="")
print(*range(i,0,-1),end=" ")
print()
passInterview problems
cried solving because it has 2 spaces not one
void numberCrown(int n) {
// Write your code here.
for(int i=1; i<=n; i++){
//number
for(int j=1; j<=i; j++){
cout<<j<<" ";
}
//space
for(int j=1; j<=(2*n-2*i); j++){
cout<<" ";
}
//number
for(int j=i; j>=1; j--){
cout<<j<<" ";
}
cout<<endl;
}
}
Interview problems
c++ code
void numberCrown(int n) {
for(int i=1;i<=n;i++){
for(int j=1;j<=i;j++){
cout<<j<<" ";
}
for(int j=0;j<2*(n-i);j++ ){
cout<<" ";
}
for(int j=i;j>=1;j--){
cout<<j<<" ";
}
cout<<endl;
}
}Interview problems
solution
void numberCrown(int n) {
// Write your code here.
for(int i=0;i<n;i++){
for(int j=1;j<=i+1;j++){
cout<<j<<" ";
}
for(int j=n;j>2*(i)-1;j--){
cout<<" ";
}
for(int j=n;j>2*(i)-1;j--){
cout<<" ";
}
for(int j=1;j<=i+1;j++){
cout<<i-j+2<<" ";
}
cout<<endl;
}
}
Interview problems
for Java users
public class Solution {
public static void numberCrown(int n) {
// Write your code here.
for (int i = 1; i <= n; i++) {
int j=0;
//numbers
for ( j = 1; j <= i; j++) {
System.out.print(j+" ");
}
//space
for (int s = n-i; s > 0; s--) {
System.out.print(" ");
}
//space
for (int s = n-i; s > 0; s--) {
System.out.print(" ");
}
//numbers
for (int k = j-1; k > 0; k--) {
System.out.print(k+" ");
}
System.out.println();
}
}
}
Interview problems
CrownPattern
void numberCrown(int n) {
// Write your code here.
for(int i=1;i<=n;i++){
//number start
for(int j=1;j<=i;j++){
cout<< j<<" ";
}
//space
for(int j=1;j<=n-i;j++){
cout<<" ";
}
for(int j=i;j>=1;j--){
cout<< j<<" ";
}
for(int j=1;j<=n-i;j++){
cout<<" ";
}
cout<<endl;
}
}
