Pattern 5

Problem

Geek is very fond of patterns. Once, his teacher gave him a pattern to solve. He gave Geek an integer n and asked him to build a pattern.

Help Geek build a star pattern.

Examples:

Example 1:

Input: 5
Output:
* * * * *
* * * * 
* * * 
* *  
* 

Example 2:

Input: 3
Output:
* * * 
* *  
* 

Your task:

You don't need to input anything. Complete the function printTriangle() which takes an integer n as the input parameter and prints the pattern.

• Expected Time Complexity: $O(n^2)$
• Expected Auxiliary Space: $O(1)$

Constraints:

• $1<= n <= 100$

Solution

Python

def printTriangle(self, N):
    for i in range(1, N + 1):
        for j in range(N, i - 1, -1):
            print("* ", end="")
        print()

Java

void printTriangle(int n) {
    for(int i = 1; i<=n; i++) {
        for(int j = n; j>=i; j--) {
            System.out.print("* ");
        }
        System.out.println();
    }
}

C++

void printTriangle(int n) {
    for(int i = 1; i<=n; i++) {
        for(int j = n; j>=i; j--) {
            cout<<"* ";
        }
        cout<<endl;
    }
}

C

void printTriangle(int n) {
    for (int i = 1; i <= n; i++) {
        for (int j = n; j >= i; j--) {
            printf("* ");
        }
        printf("\n");
    }
}

• Time Complexity: $O(n^2)$
• Auxiliary Space: $O(1)$