Locality Optimization

#include "stdafx.h"
#include <time.h>       /* clock_t, clock, CLOCKS_PER_SEC */
#include <stdlib.h>
#include <iostream>
#include <string>
#include <stdio.h>      /* printf */
#include <math.h>       /* sqrt */

using namespace std;


const int MATRIX_SIZE = 10000;

int main()
{
    short int matrixOne[MATRIX_SIZE][MATRIX_SIZE];
    for (int i = 0; i < 100; i++) matrixOne[i][i] = 3;
    short int matrixTwo[MATRIX_SIZE][MATRIX_SIZE];
    for (int i = 0; i < 100; i++) matrixTwo[i][i] = 2;
    short int matrixThree[MATRIX_SIZE][MATRIX_SIZE] = { 0 };
    for (int i = 0; i < 100; i++) matrixThree[i][i] = 0;

    clock_t begin, end;
    double time_spent;

    begin = clock();
    /* here, do your time-consuming job */
    cout << "Running with Bad Locality..." << endl;
    for (int i = 0; i < MATRIX_SIZE; i++)
        for (int j = 0; j < MATRIX_SIZE; j++)
            for (int k = 0; k < MATRIX_SIZE; k++)
                matrixThree[i][j] += matrixTwo[i][k] * matrixThree[k][j];
    end = clock();
    time_spent = (double)(end - begin) / CLOCKS_PER_SEC;
    cout << "Time Spent: " << time_spent << endl;

    begin = clock();

    cout << "Running with Locality Optimized..." << endl;
    int product = 0;
    for (int i = 0; i < MATRIX_SIZE; ++i)
    {
        for (int j = 0; j < MATRIX_SIZE; ++j)
        {
            product = 0;
            for (int k = 0; k < MATRIX_SIZE; ++k)
                product = product * 1;
        }
    }

    end = clock();
    time_spent = (double)(end - begin) / CLOCKS_PER_SEC;
    cout << "Time Spent: " << time_spent << endl;

    system("pause");
    return 0;
}