Array addition in for loop - c++

Having trouble with the last for loop. Want the total of the array values.
#include<iostream>
using namespace std;
// Arrays
int main()
{
const int numEmploye = 6;
int horas[numEmploye];
int total = 0;
for (int i = 0; i < numEmploye; i++) {
cout << "entre las horas trabajadas por el empleado " << i + 1 << ": ";
cin >> horas[i];
}
for (int i = 0; i < numEmploye; i++) {
cout << horas[i] << endl;
}
for (int i = 0; i < numEmploye; i++){
cout << total += numEmploye[i];
}
system("Pause");
return 0;
}

You're outputting the return value of the += operator. You're also using the wrong variable for the array.
for (int i = 0; i < numEmploye; i++){
total += horas[i];
}
cout << total << endl; // endl flushes the buffer

Instead of using the following, which prints the value of total += numEmploye[i]; numEmploye times...
for (int i = 0; i < numEmploye; i++){
cout << total += numEmploye[i];
}
... calculate the total first and then print that.
for (int i = 0; i < numEmploye; i++){
total += horas[i];
}
cout << total;

Also, as of C++11 you can use one of these options:
#include <numeric>
...
int total = std::accumulate(std::begin(horas), std::end(horas), 0);
std::cout << total << std::endl;
or
for (int i : horas)
total += i;
std::cout << total << std::endl;

Related

Display first even and then odd elements in a C++array

I'm a C++ newb. I need to insert numbers to an array and then display first the odd numbers and then the even numbers in a single array. I've managed to create two separate arrays with the odd and even numbers but now I don't know how to sort them and put them back in a single array. I need your help to understand how to do this with basic C++ knowledge, so no advanced functions. Here's my code:
#include <iostream>
using namespace std;
int main()
{
int N{ 0 }, vector[100], even[100], odd[100], unify[100], i{ 0 }, j{ 0 }, k{ 0 };
cout << "Add the dimension: " << endl;
cin >> N;
cout << "Add the elements: " << endl;
for (int i = 0; i < N; i++) {
cout << "v[" << i << "]=" << endl;
cin >> vector[i];
}
for (i = 0; i < N; i++) {
if (vector[i] % 2 == 0) {
even[j] = vector[i];
j++;
}
else if (vector[i] % 2 != 0) {
odd[k] = vector[i];
k++;
}
}
cout << "even elements are :" << endl;
for (i = 0; i < j; i++) {
cout << " " << even[i] << " ";
cout << endl;
}
cout << "Odd elements are :" << endl;
for (i = 0; i < k; i++) {
cout << " " << odd[i] << " ";
cout << endl;
}
return 0;
}
If you don't need to store the values then you can simply run through the elements and print the odd and the even values to different stringstreams, then print the streams at the end:
#include <sstream>
#include <stddef.h>
#include <iostream>
int main () {
std::stringstream oddStr;
std::stringstream evenStr;
static constexpr size_t vecSize{100};
int vec[vecSize] = {10, 5, 7, /*other elements...*/ };
for(size_t vecIndex = 0; vecIndex < vecSize; ++vecIndex) {
if(vec[vecIndex] % 2 == 0) {
evenStr << vec[vecIndex] << " ";
} else {
oddStr << vec[vecIndex] << " ";
}
}
std::cout << "Even elements are:" << evenStr.rdbuf() << std::endl;
std::cout << "Odd elements are:" << oddStr.rdbuf() << std::endl;
}
Storing and sorting the elements are always expensive.
Basically, it would be better to sort them first.
#include <iostream>
using namespace std;
int main()
{
int numbers[5];
int mergedArrays[5];
int evenNumbers[5];
int oddNumbers[5];
for(int i=0;i<5;i++){
cin>>numbers[i];
}
int temp=numbers[0];
//bubble sort
for(int i = 0; i<5; i++)
{
for(int j = i+1; j<5; j++)
{
if(numbers[j] < numbers[i])
{
temp = numbers[i];
numbers[i] = numbers[j];
numbers[j] = temp;
}
}
}
int nEvens=0;
int nOdds=0;
for(int i = 0; i<5; i++)
{
if(numbers[i]%2==0)
{
evenNumbers[nEvens]=numbers[i];
nEvens++;
}
else if(numbers[i]%2!=0)
{
oddNumbers[nOdds]=numbers[i];
nOdds++;
}
}
int lastIndex=0;
//copy evens
for(int i = 0; i<nEvens; i++)
{
mergedArrays[i]=evenNumbers[i];
lastIndex=i;
}
//copy odds
for(int i =lastIndex; i<nOdds; i++)
{
mergedArrays[i]=oddNumbers[i];
}
return 0;
}
If you have to just output the numbers in any order, or the order given in the input then just loop over the array twice and output first the even and then the odd numbers.
If you have to output the numbers in order than there is no way around sorting them. And then you can include the even/odd test in the comparison:
std::ranges::sort(vector, [](const int &lhs, const int &rhs) {
return ((lhs % 2) < (rhs % 2)) || (lhs < rhs); });
or using a projection:
std::ranges::sort(vector, {}, [](const int &x) {
return std::pair<bool, int>{x % 2 == 0, x}; });
If you can't use std::ranges::sort then implementing your own sort is left to the reader.
I managed to find the following solution. Thanks you all for your help.
#include <iostream>
using namespace std;
int main()
{
int N{0}, vector[100], even[100], odd[100], merge[100], i{0}, j{0}, k{0}, l{0};
cout << "Add the dimension: " << endl;
cin >> N;
cout << "Add the elements: " << endl;
for (int i = 0; i < N; i++)
{
cout << "v[" << i << "]=" << endl;
cin >> vector[i];
}
for (i = 0; i < N; i++)
{
if (vector[i] % 2 == 0)
{
even[j] = vector[i];
j++;
}
else if (vector[i] % 2 != 0)
{
odd[k] = vector[i];
k++;
}
}
cout << "even elements are :" << endl;
for (i = 0; i < j; i++)
{
cout << " " << even[i] << " ";
cout << endl;
}
cout << "Odd elements are :" << endl;
for (i = 0; i < k; i++)
{
cout << " " << odd[i] << " ";
cout << endl;
}
for (i = 0; i < k; i++)
{
merge[i] = odd[i];
}
for (int; i < j + k; i++)
{
merge[i] = even[i - k];
}
for (int i = 0; i < N; i++)
{
cout << merge[i] << endl;
}
return 0;
}
You can use Bubble Sort Algorithm to sort whole input. After sorting them using if and put odd or even numbers in start of result array and and others after them. like below:
//Bubble Sort
void bubbleSort(int arr[], int n)
{
int i, j;
for (i = 0; i < n - 1; i++)
// Last i elements are already
// in place
for (j = 0; j < n - i - 1; j++)
if (arr[j] > arr[j + 1])
swap(arr[j], arr[j + 1]);
}
// Insert In array
int result[100];
if(odd[0]<even[0])
{
for (int i = 0; i < k; i++)
{result[i] = odd[i];}
for (int i = 0; i < j; i++)
{result[i+k] = even[i];}
}else
{
for (int i = 0; i < j; i++)
{result[i] = even[i];}
for (int i = 0; i < k; i++)
{result[i+k] = odd[i];}
}

error expected primary-expression before ';'token c++

am new in coding and am using c++ to create a program to find sum median maximum and minimum but i get the error expected primary-expression before ';' token in every place that has cout
#include <iostream>
using namespace std;
int main()
{
int array[10],maximum,minimum,sum=0,median;
cout<<"input ten integers,"<<;
for(int i=0; i<10; i++){
cin>> array[i];
sum=sum+array[i];
}
for(int i=0; i<10; i++){
if(maximum>array[i])
{
maximum=array[i];
}
else if( minimum<array[i])
{
maximum= array[i];
}
}
median=(array[4]+array[5])/2;
cout<<"maximum value is"<<maximum<<;
cout<<"minimum value is"<<minimum<<;
cout<<"sum is"<<sum<<;
cout<<"median is"<median<<;
Remove the << before the ; on every line that has it or replace <<; with <<'\n'; for a new line.
#include <iostream>
using namespace std;
int main()
{
int array[10], maximum = 0, minimum = 0, sum = 0, median = 0;
cout << "input ten integers: ";
for (int i = 0; i < 10; i++) {
cin >> array[i];
sum = sum + array[i];
}
for (int i = 0; i < 10; i++) {
if (maximum > array[i])
{
maximum = array[i];
}
else if (minimum < array[i])
{
maximum = array[i];
}
}
median = (array[4] + array[5]) / 2;
cout << "maximum value is " << maximum << '\n';
cout << "minimum value is " << minimum << '\n';
cout << "sum is " << sum << '\n';
cout << "median is " << median << '\n';
return 0;
}
Use the below dummy code to fix this issue for the new line:
dummy code
#include <iostream>
int main() {
int a = 5;
int b = 10;
std::cout << (a < b) << std::endl; // 1
std::cout << (a > b) << std::endl; // 0
return 0;
}
output
1
0

C++ Integer Array Palindrome Checker

I used the following code for palindrome check of an integer array and used the value of variable 'declare' as check of palindrome. I used the technique that if declare is 1 at the end, array is palindrome, else not. But its not working. In the end of code, it always keeps the value of declare which was initialized, independent of rest of the code. Please Debug.
#include <iostream>
using namespace std;
void main()
{
int array1[3] = {0,0,1};
int j = 2;
cout << "Given Array is:\n";
for (int i = 0; i < 3; i++)
cout << array1[i];
cout << endl;
int determiner[3];
for (int i = 0; i <3; i++){
determiner[j] = array1[i];
j -= 1;
}
cout << "Reversed Array is:\n";
for (int i = 0; i < 3; i++)
cout << determiner[i];
cout << endl;
int declare;
for (int u = 0; u < 3; u++)
{
if (array1[u] = determiner[u])
{
declare = 1;
}
if (array1[u] != determiner[u])
{
declare = 0;
break;
}
}
cout << endl;
cout << declare<< endl;
if (declare==1)
cout << "Given Array is Palindrome. Cheers!!!\n";
if (declare==0)
cout << "Emhmm! This aint Palindrome.\n";
system("pause");
}
if (array1[u] = determiner[u])
should be
if (array1[u] == determiner[u])

C++ Grid Issues

I'm printing random numbers enclosed in ascii boxes in a 6x6 grid. Having issues with printing out the grid.
Instead of having 6 columns, all my boxes and numbers are being printed out in 1 column. Been troubleshooting but cant seem to find the issue. Below is the code. Appreciate your assistance.
int main(void)
{
cout << "Magic Grid\n" << endl;
int arrayxy [6][6];
srand((unsigned)time(0));
int lowest=1111, highest=9999;
int range=(highest-lowest)+1;
// Fill array with random values
for (int i = 0; i < 6; ++i)
{
for(int j = 0; j < 6; ++j)
{
arrayxy[i][j] = lowest+int(range*rand()/(RAND_MAX + 1.0));
}
}
// Print array as grid
for (int i = 0; i < 6; ++i)
{
for(int j = 0; j < 6; ++j)
{
cout << char(218);
for (int y=0; y< 4; y++)
{
cout << char(196);
}
cout << char(191) <<endl;
cout << char(179) << arrayxy[i][j] << char(179) << endl;
cout << char(192);
for (int z=0; z< 4; z++)
{
cout << char(196);
}
cout << char(217) <<endl;
}
cout << endl;
}
cout << endl;
}
You should endl after all the columns get printed out, NOT before.
This is how I fixed your code that gives, hopefully, what you wanted to have.
For the record, I specifically changed those ASCII to * and & to make the console result more readable. You can change them back to what you want those characters to be again.
void WriteFrontLine(std::size_t count)
{
for (int i = 0; i < count; i++)
{
cout << '*';
cout << '&' << '&' << '&' << '&';
cout << '*';
}
cout << endl;
}
void WriteEndLine(std::size_t count)
{
for (int i = 0; i < count; i++)
{
cout << '*';
cout << '&' << '&' << '&' << '&';
cout << '*';
}
cout << endl;
}
int main(void)
{
cout << "Magic Grid\n" << endl;
int arrayxy[6][6];
srand((unsigned)time(0));
int lowest = 1111, highest = 9999;
int range = (highest - lowest) + 1;
// Fill array with random values
for (int i = 0; i < 6; ++i)
{
for (int j = 0; j < 6; ++j)
{
arrayxy[i][j] = lowest + int(range*rand() / (RAND_MAX + 1.0));
}
}
// Print array as grid
for (int i = 0; i < 6; ++i)
{
WriteFrontLine(6);
for (int j = 0; j < 6; ++j)
{
cout << '*' << arrayxy[i][j] << '*';
}
cout << endl;
WriteEndLine(6);
cout << endl;
}
cout << endl;
}

Print an array in C++

I'm trying to do some of my C++ homework, but I seem to have run into an issue. I need to make it so that the user inputs 8 numbers, and those said 8 get stored in an array. Then, if one of the numbers is greater than 21, to output said number. The code is below, and it's kind of sloppy. Yes, first year C++ learner here :p
#include <iostream>
using namespace std;
int main() {
const int NUM_ELEMENTS = 8; // Number of elements
int userVals[NUM_ELEMENTS]; // User numbers
int i = 0; // Loop index
int sumVal = 0; // For computing sum
int prntSel = 0; // For printing greater than 21
// Prompt user to populate array
cout << "Enter " << NUM_ELEMENTS << " integer values..." << endl;
for (i = 0; i < NUM_ELEMENTS; ++i) {
cin >> userVals[i];
}
for (int i = NUM_ELEMENTS - 1; i > 21; i--)
cout << "Value: " << sumVal << endl;
// Determine sum
sumVal = 0;
for (i = 0; i < NUM_ELEMENTS; ++i) {
sumVal = sumVal + userVals[i];
}
cout << "Sum: " << sumVal << endl;
return 0;
}
Don't reinvent the wheel, use standard algorithms:
std::copy_if(std::begin(userVals), std::end(userVals),
std::ostream_iterator<int>(std::cout, "\n"),
[] (auto x) { return x > 21; });
I improved the rest of your program as well:
#include <algorithm>
#include <iostream>
#include <iterator>
#include <numeric>
#include <vector>
auto constexpr count = 8;
int main() {
std::vector<int> numbers(count);
std::cout << "Enter " << count << " integer values...\n";
std::copy_n(std::istream_iterator<int>(std::cin), numbers.size(), numbers.begin());
std::copy_if(numbers.begin(), numbers.end(),
std::ostream_iterator<int>(std::cout, "\n"),
[] (auto x) { return x > 21; });
auto sum = std::accumulate(numbers.begin(), numbers.end(), 0);
std::cout << "Sum: " << sum << '\n';
return 0;
}
See it live on Coliru!
Ok, I'm going to explain this to you and keep it simple. This loop
`for (int i = NUM_ELEMENTS - 1; i > 21; i--)`
will never execute because in your first iteration you are checking if (NUM_ELEMENTS-1=7)>21. You are then decrementing i so this will take the series (6,5,4,...) and nothing would ever happen here.
If you have to sum the numbers greater than 21, which I presume is what you need then you will have to remove the above loop and modify your second loop to:
for (i = 0; i < NUM_ELEMENTS; i++) {
if(userVals[i]>21)
sumVal = sumVal + userVals[i];
}
This way, you add the numbers in the array that are only greater than 21. The index of userVals is determined by the i variable which also acts as a counter.
You're on the right track. There's just a few things wrong with your approach.
#include <iostream>
#include <stdlib.h>
using namespace std;
int main() {
const int NUM_ELEMENTS = 8;
int userVals[NUM_ELEMENTS];
int i = 0;
int sumVal = 0;
int prntSel = 0;
int size = sizeof(userVals) / sizeof(int); // Get size of your array
// 32/4 = 8 (ints are 4 bytes)
cout << "Enter " << NUM_ELEMENTS << " integer values..." << endl;
for (i = 0; i < NUM_ELEMENTS; ++i) {
cin >> userVals[i];
}
for(int i = 0; i < size; i++) {
if(userVals[i] > 21) { // Is number > 21?
cout << userVals[i] << endl; // If so, print said number
exit(0); // And exit
}
else
sumVal += userVals[i]; // Else sum your values
}
cout << "Sum: " << sumVal << endl;
return 0;
}
#include <iostream>
using namespace std;
int main() {
const int NUM_ELEMENTS = 8; // Number of elements
int userVals[NUM_ELEMENTS]; // User numbers
int i = 0; // Loop index
int sumVal = 0; // For computing sum
int prntSel = 0; // For printing greater than 21
// Prompt user to populate array
cout << "Enter " << NUM_ELEMENTS << " integer values..." << endl;
for (i = 0; i < NUM_ELEMENTS; ++i) {
cin >> userVals[i];
}
// for (int i = NUM_ELEMENTS - 1; i > 21; i--)
// cout << "Value: " << sumVal << endl;
for( i = 0; i < NUM_ELEMENTS; ++i )
{
if( userVals[ i ] > 21 )
{
cout << "Value: " << i << " is " << userVals[ i ] << endl;
}
}
for (i = 0; i < NUM_ELEMENTS; ++i) {
sumVal = sumVal + userVals[i];
}
cout << "Sum: " << sumVal << endl;
return 0;
}
Try
for (int i = NUM_ELEMENTS - 1; i > 21; i--)
cout << "Value: " << sumVal << endl;
to
for (i = 0; i < NUM_ELEMENTS; ++i) {
if(userVals[i] > 21)
cout << "Value: " << userVals[i] << endl;
}
This line isnt needed as well, as you arent using it.
int prntSel = 0; // For printing greater than 21
for (int i = NUM_ELEMENTS - 1; i > 21; i--)
cout << "Value: " << sumVal << endl;
Here you are printing the value of sumVal, not the value of the array in the position i. The line should be:
cout << "Value: " << usersVals[i] << endl;
Also that that your for is not doing what you think it does. for doesn't use the condition you gave to decide if will execute the current iteration or not, it uses the condition to decide if the loop should continue or not. So when you put i > 21, means that it will continue running while i is bigger than 21. To achieve your goal, you should make a test (if statement) inside the loop.
The final result it would be:
for (i = 0; i < NUM_ELEMENTS; ++i) {
if (usersVals[i] > 21) {
cout << "Value: " << usersVals[i] << endl;
}
}