Hi

I am developing a program that uses Breadth First Search to map a grid(2d array) out. Breadth First Search involves storing nodes in a stack and then exploring these nodes based on Breadth or level. I know how to create a vector array which I shall use as a stack. I need to know how to store array elements in the stack using the

push_back()

method. This is what I have so far..

vector<int>stack; //stack initialization.
stack.push_back(array[1][1]) //store array element itself, not Value held in array!

The value stored is not the array element, but the value which happens to be some integer x.

Thanks for helping.

if you want to store the address of that element in you vector than you can do

vector<int*> stack
stack.push_back(&(array[1][1]))

if you are trying to store the value of x and y values you can use a 2d vector like

vector< vector<int> > stack
vector<int> temp;
if (array[x][y] == something)
{
    temp.push_back(x);
    temp.push_back(y);
    stack.push_back(temp);
    temp.clear();
}

although this might not be the best way to do it.

Comments
Great helpful post

Why would you want to simulate a stack for a vector if there is already an implemented stack?!

#include <stack>
#include <iostream>
int main()
{
 std::stack<int>  st;
 st.push(1);
 st.push(3);
 std::cout << st.top() << std::endl; // outputs 3;
 st.pop();
 std::cout << st.top() << std::endl; //outputs1
}

Why would you want to simulate a stack for a vector if there is already an implemented stack?!

#include <stack>
#include <iostream>
int main()
{
 std::stack<int>  st;
 st.push(1);
 st.push(3);
 std::cout << st.top() << std::endl; // outputs 3;
 st.pop();
 std::cout << st.top() << std::endl; //outputs1
}

Well I looked into it, but for a Breadth First Search I need a FIFO(First In First Out) type stack. The one above is LIFO. So unless there is actually a FIFO stack, which I think only exists in a queue, I wont be using any stacks.

Thanks for replying.

if you want to store the address of that element in you vector than you can do

vector<int*> stack
stack.push_back(&(array[1][1]))

if you are trying to store the value of x and y values you can use a 2d vector like

vector< vector<int> > stack
vector<int> temp;
if (array[x][y] == something)
{
    temp.push_back(x);
    temp.push_back(y);
    stack.push_back(temp);
    temp.clear();
}

although this might not be the best way to do it.

Great post, both methods worked, although the pointer method is more efficient. I knew pointers were the answer, thanks for showing me how!

Thanks for replying.

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