translating algorithm for C++ nested while loop diamond pattern - c++

Question

Here is my homework problem for C++:
The following algorithm is a solution to a problem that uses nested loops to display a diamond pattern. Translate the algorithm below in to a C++ program. Build, run and test the program.
Algorithm Solution:
Start
Declare numRows as constant integer = 7
Declare maxPlus as constant integer = 7
Declare numSpaces as integer
Declare numPluses as integer
Declare row as integer
Declare space as integer
Declare plus as integer
Set row = 1
Repeat while row >= 1 AND row <= numRows
Set numPluses = 2 * row - 1
if(numPluses > maxPlus) then
Set numPluses = 14 - numPluses
endif
Set numSpaces = (maxPlus - numPluses) / 2
Set space = 1
Repeat while space >= 1 AND space <= numSpaces
Display( ' ')
Set space = space + 1
End Repeat
Set plus = 1
Repeat while plus >= 1 AND plus <= numPluses
Display( '*')
Set plus = plus + 1
End Repeat
Set row = row + 1
Display a new line
End Repeat
Stop
My code:
#include <iostream>
using namespace std;
int main() {
const int numRows = 7;
const int maxPlus = 7;
int numSpaces;
int numPluses;
int row;
int space;
int plus;
row = 1;
while((row >=1) && (row <= numRows)){
numPluses = 2 * row - 1;
if(numPluses > maxPlus){
numPluses = 14 - numPluses;
}
numSpaces = (maxPlus - numPluses)/ 2;
space = 1;
while((space >= 1) && (space <= numSpaces)){
cout << " ";
space++;
}
while((plus >= 1) && (plus <= numPluses)){
cout << "*";
plus++;
}
row++;
cout << endl;
}
return 0;
}
My question is why am I not getting the diamond pattern? I feel like I translated the algorithm correctly, but all I get is a bunch of blank space. Did I read the problem wrong or did I code wrong? screenshot of C++ code

Answer 1

Before the last while loop:
Set plus = 1
You missed that in your translation.

Answer 2

The code did not initialize plus.
There's a habit that saves much grief. Never declare a variable without giving it a meaningful initial value at the point of definition. Limit the scope of variables to where they are actually used. When translating pseudo-code, that can mean doing a little bit of re-writing. Diggit.
int main() {
const int numRows = 7;
const int maxPlus = 7;
for (int row = 1; row <= numRows; ++row) {
const int trianglePluses = 2 * row - 1;
const int numPluses = trianglePluses <= maxPlus
? trianglePluses
: 2 * numRows - trianglePluses;
const int numSpaces = (maxPlus - numPluses) / 2;
for(int space=1; space <= numSpaces; ++space) {
cout << " ";
}
for (int plus = 1; plus <= numPluses; ++plus) {
cout << "*";
}
cout << endl;
}
return 0;
}