ICSE Class 10 Computer Applications
Question 21 of 22
Nested for loops — Question 21
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Question Question 10
Write a menu driven program that prompts the user to select one of the four triangle patterns (a, b, c or d). The program then accepts number of rows and prints the selected pattern as shown below:
Enter the size: 8
(a)
1
1 2
1 2 3
1 2 3 4
1 2 3 4 5
1 2 3 4 5 6
1 2 3 4 5 6 7
1 2 3 4 5 6 7 8
(b)
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7
1 2 3 4 5 6
1 2 3 4 5
1 2 3 4
1 2 3
1 2
1
(c)
1
1 2
1 2 3
1 2 3 4
1 2 3 4 5
1 2 3 4 5 6
1 2 3 4 5 6 7
1 2 3 4 5 6 7 8
(d)
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7
1 2 3 4 5 6
1 2 3 4 5
1 2 3 4
1 2 3
1 2
1
import java.util.Scanner;
public class KboatTriangleChoice
{
public static void main(String args[]) {
Scanner in = new Scanner(System.in);
System.out.println("Type a for Pattern a");
System.out.println("Type b for Pattern b");
System.out.println("Type c for Pattern c");
System.out.println("Type d for Pattern d");
System.out.print("Enter your choice: ");
char ch = in.next().charAt(0);
System.out.print("Enter the number of terms: ");
int n = in.nextInt();
switch (ch) {
case 'a':
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= i; j++)
System.out.print(j);
System.out.println();
}
break;
case 'b':
for (int i = n; i >= 1; i--) {
for (int j = i; j < n; j++)
System.out.print(" ");
for (int k = 1; k <= i; k++)
System.out.print(k);
System.out.println();
}
break;
case 'c':
for (int i = 1; i <= n; i++) {
for (int j = i; j < n; j++)
System.out.print(" ");
for (int k = 1; k <= i; k++)
System.out.print(k);
System.out.println();
}
break;
case 'd':
for (int i = n; i >= 1; i--) {
for (int j = 1; j <= i; j++)
System.out.print(j);
System.out.println();
}
break;
default:
System.out.println("Incorrect choice");
break;
}
}
}Output
