Question

What would happen to the time complexity (Big-oh) of the methods (push, pop) in an array implementation of the stack if the top of the stack were at position 0? Explain.

Answer 1

//This code is in java
public boolean push(int data){
    if (num < cap-1){
        stack[++num] = data;
        return true;
    }
    return false;
}

public int pop(){
    if (num >= 0){
        return stack[num--];
    }
    return

}

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1 Push:

Adds a value at the end of the array, and incrementing the stack pointer by 1

So, time complexity = O(1)

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2 Pop:

Decrementing the stack pointer by 1

So, time complexity = O(1)

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