go/test/bench/binary-tree.c

/*
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    * Neither the name of "The Computer Language Benchmarks Game" nor the
    name of "The Computer Language Shootout Benchmarks" nor the names of
    its contributors may be used to endorse or promote products derived
    from this software without specific prior written permission.

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*/

/* The Computer Language Shootout Benchmarks
   http://shootout.alioth.debian.org/

   contributed by Kevin Carson
   compilation:
       gcc -O3 -fomit-frame-pointer -funroll-loops -static binary-trees.c -lm
       icc -O3 -ip -unroll -static binary-trees.c -lm
*/

#include <malloc.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>


typedef struct tn {
    struct tn*    left;
    struct tn*    right;
    long          item;
} treeNode;


treeNode* NewTreeNode(treeNode* left, treeNode* right, long item)
{
    treeNode*    new;

    new = (treeNode*)malloc(sizeof(treeNode));

    new->left = left;
    new->right = right;
    new->item = item;

    return new;
} /* NewTreeNode() */


long ItemCheck(treeNode* tree)
{
    if (tree->left == NULL)
        return tree->item;
    else
        return tree->item + ItemCheck(tree->left) - ItemCheck(tree->right);
} /* ItemCheck() */


treeNode* BottomUpTree(long item, unsigned depth)
{
    if (depth > 0)
        return NewTreeNode
        (
            BottomUpTree(2 * item - 1, depth - 1),
            BottomUpTree(2 * item, depth - 1),
            item
        );
    else
        return NewTreeNode(NULL, NULL, item);
} /* BottomUpTree() */


void DeleteTree(treeNode* tree)
{
    if (tree->left != NULL)
    {
        DeleteTree(tree->left);
        DeleteTree(tree->right);
    }

    free(tree);
} /* DeleteTree() */


int main(int argc, char* argv[])
{
    unsigned   N, depth, minDepth, maxDepth, stretchDepth;
    treeNode   *stretchTree, *longLivedTree, *tempTree;

    N = atol(argv[1]);

    minDepth = 4;

    if ((minDepth + 2) > N)
        maxDepth = minDepth + 2;
    else
        maxDepth = N;

    stretchDepth = maxDepth + 1;

    stretchTree = BottomUpTree(0, stretchDepth);
    printf
    (
        "stretch tree of depth %u\t check: %li\n",
        stretchDepth,
        ItemCheck(stretchTree)
    );

    DeleteTree(stretchTree);

    longLivedTree = BottomUpTree(0, maxDepth);

    for (depth = minDepth; depth <= maxDepth; depth += 2)
    {
        long    i, iterations, check;

        iterations = pow(2, maxDepth - depth + minDepth);

        check = 0;

        for (i = 1; i <= iterations; i++)
        {
            tempTree = BottomUpTree(i, depth);
            check += ItemCheck(tempTree);
            DeleteTree(tempTree);

            tempTree = BottomUpTree(-i, depth);
            check += ItemCheck(tempTree);
            DeleteTree(tempTree);
        } /* for(i = 1...) */

        printf
        (
            "%li\t trees of depth %u\t check: %li\n",
            iterations * 2,
            depth,
            check
        );
    } /* for(depth = minDepth...) */

    printf
    (
        "long lived tree of depth %u\t check: %li\n",
        maxDepth,
        ItemCheck(longLivedTree)
    );

    return 0;
} /* main() */