stack.cpp

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#include "defines.h"
#ifdef LOGGING
#include "log.h"
#endif
#include "stack.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

int initialize_Stack(struct stack_T *stack, int size)
{
    int     ret=SUCCESS;        // Return value.

    // Initialize stack attributes.
    stack->size = size;
    stack->nElements = 0;
    stack->data = (struct Convex_T *) malloc(sizeof(struct Convex_T)*size);

    // Check error allocating memory.
    if (stack->data == NULL)
    {
        ret = FAILURE;
        printf("Error allocating memory in initialize_Stack");
#ifdef LOGGING
        sprintf( log_Text, "Error allocating memory in initialize_Stack\n");
        write_Log( log_Text);
#endif
    }

    return(ret);
}

struct Convex_T     peak(struct stack_T *stack)
{
    // Get peak element of the stack.
    return(stack->data[stack->nElements-1]);
}

struct Convex_T     peak_Prev(struct stack_T *stack)
{
    // Get the top 2 elements of the stack.
    return(stack->data[stack->nElements-2]);
}

void    update_Peak(struct stack_T *stack, int edge)
{
    // Update edge of peak of the stack.
    stack->data[stack->nElements-1].edge_ID = edge;
}

void    push(struct stack_T *stack, struct Convex_T edge)
{
    // Insert a new element in the top of the stack.
    stack->data[stack->nElements] = edge;
    stack->nElements++;
}


void    pop(struct stack_T *stack)
{
    // Check if stack is not empty.
    if (stack->nElements > 0)
    {
        // Decrease number of elements.
        stack->nElements--;
    }
}

int     get_Stack_nElements(struct stack_T *stack)
{
    // Return number of elements.
    return(stack->nElements);
}

void    reset_Stack(struct stack_T *stack)
{
    // Reset data of the stack (without resizing).
    stack->nElements = 0;
    memset( stack->data, 0, sizeof(struct Convex_T)*stack->size);
}

void    print_Stack(struct stack_T *stack)
{
    int i=0;                    // Loop counter.

    // Print all elements in stack.
    for (i=0; i<stack->nElements ;i++)
    {
        printf("Position: %d. Edge id: %d with origin vertex %d.\n",
                                            i,
                                            stack->data[i].edge_ID,
                                            stack->data[i].vertex_Index);
    }
}

void    finalize_Stack(struct stack_T *stack)
{
    // Deallocate memory.
    stack->size = 0;
    stack->nElements = 0;
    if (stack->data != NULL)
    {
        free(stack->data);
        stack->data = NULL;
    }
}