[求助][讨论]如何使两个for并行执行?

#include <Windows.h>
#include <iostream>
using std::cout;
using std::endl;
typedef struct _Mutex
{
    LPTSTR lpStr;
    HANDLE mutex;
    _Mutex(LPTSTR s,HANDLE m){lpStr=s;mutex=m;}
}* _PMutex;
DWORD WINAPI f1(LPVOID lp)
{
   
    for (int i=0;i<100;i++)
    {
        WaitForSingleObject(_PMutex(lp)->mutex,INFINITE);
        cout<<_PMutex(lp)->lpStr<<i<<endl;
        ReleaseMutex(_PMutex(lp)->mutex);
    }
   
    return 0;
}
DWORD WINAPI f2(LPVOID lp)
{
    for (int i=0;i<100;i++)
    {
        WaitForSingleObject(_PMutex(lp)->mutex,INFINITE);
        cout<<_PMutex(lp)->lpStr<<i<<endl;
        ReleaseMutex(_PMutex(lp)->mutex);
    }
    return 0;
}
void main()
{
    HANDLE hMutex=CreateMutex(NULL,FALSE,NULL);
    HANDLE hThread1=CreateThread(NULL,0,f1,(LPVOID)new _Mutex(\"first: \",hMutex),0,NULL);
    HANDLE hThread2=CreateThread(NULL,0,f1,(LPVOID)new _Mutex(\"second: \",hMutex),0,NULL);
    Sleep(1000);
    CloseHandle(hThread1);
    CloseHandle(hThread1);
}