C++ Vector Exercises: Consecutive Numbers in a vector

C++ Vector: Exercise-1 with Solution

Write a C++ program to check whether numbers in a vector can be rearranged so that each number appears exactly once in a consecutive list of numbers. Return true otherwise false.

Sample Data:
{1, 2 ,5, 7, 4, 3, 6} -> true
{1, 2 ,5, 0, 3, 6, 7} ->false

Visual Presentation:

Sample Solution-1:

C++ Code:

#include <algorithm>    // Including the Algorithm Library for sorting
#include <iostream>     // Including the Input/Output Stream Library
#include <vector>       // Including the Vector Library for using vectors
using namespace std;    // Using the Standard Namespace

// Function to test if the elements in the vector are consecutive
bool test(std::vector<int> nums) {
    std::sort(nums.begin(), nums.end()); // Sorting the elements of the vector in ascending order

    // Loop through the vector to check if elements are consecutive
    for (int i = 0; i < nums.size() - 1; i++) {
        if (nums[i + 1] != (nums[i] + 1)) {
            return false; // If the elements are not consecutive, return false
        }
    }
    return true; // If all elements are consecutive, return true
}

// Main function
int main() {
    // Declaring a vector of integers and initializing it with values
    // Uncomment either of the following lines to test different sets of numbers

    // vector<int> nums = {1, 2 ,5, 7, 4, 3, 6}; // Test vector with non-consecutive numbers
    vector<int> nums = {1, 2 ,5, 0, 3, 6, 7}; // Test vector with consecutive numbers

    // Printing the elements of the vector
    for (int x : nums)
        cout << x << " ";
    cout << "\nCheck consecutive numbers in the said vector! " << test(nums) << endl; // Calling the test function to check if elements are consecutive and displaying the result
}

Sample Output:

1 2 5 0 3 6 7 
Check consecutive numbers in the said vector! 0

Flowchart:

Sample Solution-2:

C++ Code:

#include <algorithm>   // Include the algorithm header for the sort function
#include <iostream>    // Include the iostream header for input and output operations
#include <vector>      // Include the vector header for using the vector container
using namespace std;   // Use the std namespace to simplify code
bool test(std::vector<int> nums)
{
    std::sort(nums.begin(), nums.end());  // Sort the elements of the vector in ascending order
    int last = nums.at(0) - 1;            // Initialize a variable to store the last value, set to one less than the first element
    for (int number : nums) {
        if ((number - last) != 1)          // Check if the current number is not one greater than the last one
            return false;                  // If not, the numbers are not consecutive, so return false
        last = number;                     // Update the last value to the current number for the next iteration
    }
    return true;                           // If all numbers are consecutive, return true
}
int main(){
    vector<int> nums = {1, 2 ,5, 7, 4, 3, 6};  // Initialize a vector with a set of integers
    //vector<int> nums = {1, 2 ,5, 0, 3, 6, 7};  // Another set of integers for testing
    for (int x : nums)
        cout << x << " ";                 // Print each element of the vector
    cout << "\nCheck consecutive numbers in the said vector! "<< test(nums) << endl;   // Check and display if the numbers are consecutive
}

Sample Output:

1 2 5 7 4 3 6 
Check consecutive numbers in the said vector! 1

Flowchart:

C++ Code Editor:

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