PO zad. 2.1

#include "stdafx.h"
#include <stdlib.h>
#include <Windows.h>
#include <stdio.h>

int suma;
int t[10000];

CRITICAL_SECTION cs;

DWORD WINAPI ThreadFunc(LPVOID lpdwParam) {
    int tid = (int)lpdwParam;
    int s = 0;
    int i;
    int dn = 10000 / 4;
    int start = tid*dn;
    int stop = tid != 4 - 1 ? (tid + 1)*dn : 10000;

    for (i = start; i<stop; i++) s += t[i];
    EnterCriticalSection(&cs);
    suma += s;
    LeaveCriticalSection(&cs);
    return 0;
}

int _tmain(int argc, _TCHAR* argv[])
{
    DWORD dwThreadId, dwThrdParam[4];
    HANDLE ahThreads[4];

    InitializeCriticalSection(&cs);

    int i, s = 0, z = 100;
    for (i = 0; i<10000; i++) t[i] = rand() % z;

    s = 0;
    for (i = 0; i<10000; i++) s += t[i];
    printf("Suma wyliczona w watku 1: %d\n", s);

    suma = 0;

    for (i = 0; i<4; i++)
    {
        dwThrdParam[i] = i;
        ahThreads[i] = CreateThread(NULL, 0, ThreadFunc, (LPVOID)dwThrdParam[i], 0, &dwThreadId);
    }

    for (i = 0; i<4; i++)
    {
        WaitForSingleObject(ahThreads[i], INFINITE);
    }
    printf("Suma  wyliczona w watku 2: %d\n", suma);

    DeleteCriticalSection(&cs);
    system("pause");
    return 0;
}