C++ Two dimensional array multiplication table - c++

Question

I am using C++ and want to do a 2-dimensional array. 10 rows and 3 columns. First column is(1 through 10). For Second column, user enters his/her choice of a number from (1-10) resulting in a times table displaying the results as follows: In this example the user's choice is '4':
1x4=4
2x4=8
3x4=12
4x4=16
5x4=20
6x4=24
7x4=28
8x4=32
9x4=36
10x4=40
I can't get the user's input to calculate correctly when using the for loop.

Answer 1

Well you can try this to get that output
#include<iostream>
using namespace std;
int main()
{
int n; //To take input
int table[10][3]; // Table
cout << "Input a number: ";
cin >> n;
// Generating Output
for (int i = 0; i < 10; i++)
{
table[i][0] = i + 1;
table[i][1] = n;
table[i][2] = table[i][0] * table[i][1];
}
for (int i = 0; i < 10; i++)
{
cout << table[i][0] << " * " << table[i][1] << " = " << table[i][2]<<endl;
}
return 0;
}
Output

Answer 2

SOLVED: Everything seems to be working now!! Here's the code:
#include <iostream>
#include<cstdlib>
#include<iomanip>
#include <ctime>
using namespace std;
void displayTable(int table[10][3]);
bool testMe(int testTable[10][3]);
void createTables(int testTable[10][3], int ansTable[10][3], int
usersChoice);
bool AllAnswersAreTested(bool tested[10]);
void gradeMe(int testTable[10][3], int ansTable[10][3]);
void displayMenu();
int main()
{
srand(time(NULL));
int userInput = 0;
int tableChoice = 0;
int myTable[10][3] = {0};
int testTable[10][3];
int ansTable[10][3];
bool tested = false;
do
{
displayMenu(); //Display the menu of choices
cin >> userInput;
cout << endl;
switch (userInput) //Validate menu choices 1-4
{
case 1: //Display a users choice of table
displayTable(myTable);
break;
case 2: //Test user on users choice of table
cout << "What times table test would you like to take? > ";
cin >> tableChoice;
createTables(testTable, ansTable, tableChoice);
tested = testMe(testTable);
if (tested)
{
gradeMe(testTable, ansTable);
}
break;
case 3: //Display a new table of the users choice
displayTable(myTable);
break;
case 4: //Quit program menu option
cout << "Program ending.\n";
return 0;
default: //Invalid entry
cout << "You entered an invalid item number. Please enter a number from 1 to 4.\n";
cout << endl;
}
} while (userInput != 4);
return 0;
}
void displayTable(int myTable[10][3])
{
int num; //initialize local variables
//Ask the user what times table they would like to review
cout << "What times table would you like to review?" << endl;;
cout << "Please enter a value from 1 to 12 > \n";
cout << "\n";
cin >> num;
cout << endl;
for (int i = 0; i < 10; i++)
{
myTable[i][0] = i + 1;
myTable[i][1] = num;
myTable[i][2] = myTable[i][0] * myTable[i][1];
}
for (int i = 0; i < 10; i++)
{
cout << setw(3)<< myTable[i][0] << " * " << myTable[i][1] << " = " << myTable[i][2] << endl;
}
cout << endl;
}
void createTables(int testTable[10][3], int ansTable[10][3], int usersChoice)
{
for (int i = 0; i < 10; i++)
{
testTable[i][0] = i + 1;
testTable[i][1] = usersChoice;
testTable[i][2] = 0;
ansTable[i][0] = i + 1;
ansTable[i][1] = usersChoice;
ansTable[i][2] = usersChoice * (i + 1);
}
}
bool testMe(int testTable[10][3])
{
bool tested[10] = { false, false, false, false, false,false, false, false, false, false };
while (!AllAnswersAreTested(tested))
{
int index = rand() % 10;
if (tested[index] == false)
{
int randomNum = testTable[index][0];
int tableChoice = testTable[index][1];
int answer;
cout << "What is " << randomNum << " X " << tableChoice << " = ";
cin >> answer;
testTable[index][2] = answer;
tested[index] = true;
}
}
return true;
}
bool AllAnswersAreTested(bool tested[10])
{
for (int i = 0; i < 10; i++)
{
if (tested[i] == false)
{
return false;
}
}
return true;
}
void gradeMe(int testTable[10][3], int ansTable[10][3])
{
int correctAnswers = 0;
for (int i = 0; i<10; i++)
{
if (testTable[i][2] == ansTable[i][2])
{
correctAnswers++;
}
}
int score = (correctAnswers * 10);
if (score == 100)
{
cout << "You passed the test! PERFECT SCORE!!" << endl;
cout << endl;
}
else if (score >= 70)
{
cout << "You passed the test. Your Score is: ";
cout << score;
cout << endl;
}
else if (score < 70)
{
cout << "You did not pass the test. Your Score is: ";
cout << score;
cout << endl;
}
}
//Display the menu function
void displayMenu()
{
cout << " Multiplication Tables" << endl;
cout << endl;
cout << " 1. Review MyTable" << endl;
cout << " 2. Test Me" << endl;
cout << " 3. Enter a New Multiplication Table (1-12)";
cout << " 4. Quit" << endl;
cout << " Enter a Menu Item > ";
}

Answer 3

#include <iostream>
using namespace std;
int main()
{
int a[100][100];
for(int i=1;i<10;i++){
for(int j=1;j<10;j++){
a[i][j] = (i)*(j);
cout<<a[i][j]<<" ";
}
cout<<endl;
}
return 0;
}
There is how the output looks like: