Question

Write a function named swapFrontBack that takes as input an array of integers and an integer that specifies how many entries are in the array. The function should swap the first element in the array with the last element in the array. The function should check if the array is empty to prevent errors. Test your function with arrays of different length and with varying front and back numbers.

Answer 1

#include <iostream>

#include <vector>

using namespace std;

void swapFrontBack(vector<int>& nums) {

if(nums.size() < 2) {

return;

}

swap(nums[0], nums[nums.size()-1]);

}

void printit(vector<int>& arr) {

for(int i = 0; i < arr.size(); i++) {

cout << arr[i] << " ";

}

cout << endl;

}

int main() {

vector<int> num1;

swapFrontBack(num1);

printit(num1);

num1.push_back(1);

swapFrontBack(num1);

printit(num1);

num1.push_back(2);

swapFrontBack(num1);

printit(num1);

vector<int> num2(10, 1);

num2[9] = 2;

swapFrontBack(num2);

printit(num2);

return 0;

}

Step-by-step explanation: