C++ Exercises: Create and display unique three-digit number using 1, 2, 3, 4

Last update on April 07 2025 13:00:59 (UTC/GMT +8 hours)

87. Generate Three-Digit Numbers from {1,2,3,4} and Count Them

Write a C++ program to create and display an original three-digit numbers using 1, 2, 3, 4. Also count how many three-digit numbers are there.

Visual Presentation:

C++ Exercises: Create and display unique three-digit number using 1, 2, 3, 4

Sample Solution:-

C++ Code :

#include <iostream>
using namespace std;

// Function prototype declaration to reverse a string
void revOfString(const string& a);

int main() {
    // Declaration of string variable to store output
    string str;

    // Displaying the purpose of the code
    cout << "\n\n Create and display the unique three-digit number using 1, 2, 3, 4:\n";
	cout << "-------------------------------------------------------------------\n";
	
    // Displaying the prompt for three-digit numbers
	cout << " The three-digit numbers are: " << endl;
	
    // Initializing variable 'amount' to count the unique three-digit numbers
	int amount = 0;
	cout << " "; // Formatting output

	// Loop to generate and display unique three-digit numbers
	for (int i = 1; i <= 4; i++) {
		for (int j = 1; j <= 4; j++) {
			for (int k = 1; k <= 4; k++) {
				// Checking for unique digits in each position (i, j, k)
				if (k != i && k != j && i != j) {
					amount++; // Incrementing the count of unique numbers
					cout << i << j << k << " "; // Displaying the unique number
				}
			}
		}
	}
	
	// Displaying the total count of unique three-digit numbers
	cout << endl << " Total number of the three-digit numbers is: " << amount << endl << endl;
}

Sample Output:

 Create and display the unique three-digit number using 1, 2, 3, 4:    
-------------------------------------------------------------------    
 The three-digit numbers are:                                          
 123 124 132 134 142 143 213 214 231 234 241 243 312 314 321 324 341 34
2 412 413 421 423 431 432                                              
 Total number of the three-digit-number is: 24

Flowchart:

For more Practice: Solve these Related Problems:

Write a C++ program to generate all unique three-digit numbers using the digits 1, 2, 3, and 4 without repetition, and count them.
Write a C++ program that creates all possible three-digit permutations from the set {1,2,3,4} and prints the total count.
Write a C++ program to generate and display all three-digit numbers formed by the digits 1 to 4, ensuring no digit is repeated in a number.
Write a C++ program that uses nested loops to form three-digit numbers from {1,2,3,4} and then outputs the number of such unique combinations.

C++ Code Editor:

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