thread to each that will calc the prime numbers 100

Question

Windows Form with 3 labels that will each be used to show a number. Assign a worker thread to each that will calculate the prime numbers less than a 1000.

Mukil Vendhan · Answer

solution 1: #include #include #include using namespace std; const int MAX = 10000; struct prArray { int pStart, pEnd, pTest, pCount; int tArray[MAX]; }; int check_prime( int ); DWORD WINAPI primer(LPVOID lpParam); int main() { /* by having these 2 variables + the struct, error checkin is made easier*/ int one, two, diff, temp, end1, start2; cout " START:
" ; cin >> one; cin >> two; prArray ash; prArray jeff; diff = (two - one); // get the difference between the start and end values temp = diff / 2; // use this to divide the work evenly among the threads end1 = one + temp; // end value for first thread start2 = end1 + 1; // begin 1 number after the end of first thread // set the struct values ash.pStart = one; // equal to the first number of the range e.g. 1 - 10000 --> 1 ash.pEnd = one + temp; // equal to halfway between the range e.g. 5000 ash.pCount = ash.pStart; jeff.pStart = start2; // equal to next number after halfway e.g. 5001 jeff.pEnd = two; // equal to last number of the range e.g. 10000 jeff.pCount = jeff.pStart; //create first thread DWORD myThreadID1; HANDLE myHandle = CreateThread( NULL, // security 0, // stack size primer, // function to perform &ash, // function parameter --> pass the struct 0, // creation flag &myThreadID1); // thread id //create second thread DWORD myThreadID2; HANDLE myHandle2 = CreateThread( 0, 0, primer, &jeff, 0, &myThreadID2); // close the threads CloseHandle(myHandle); CloseHandle(myHandle2); // print stuff out cout cout " BACK TO main()
" ; // begin with first struct (ash) cout "
 THREAD1: 
" ; cout "Thread1 starting point: " cout "Thread1 ending point: " cout "Test: " int i1; for (i1 = 0; i1 // print array values for first struct (ash) { if (ash.tArray[i1] == 0) { break ; } else { cout " " ; } } //begin second thread (jeff) cout cout " THREAD2: " cout "Thread2 starting point: " cout "Thread2 ending point: " cout "Test: " int js; for (js = 0; js // print array values for second struct (jeff) { if (jeff.tArray[js] == 0) { break ; } else { cout " " ; } } cout "
 first = " cout " second = " cout "Thread 1 counter = " cout "Thread 2 counter = " cout "
 END PROGRAM" system( "pause" ); return 0; } // ============= END OF main() ============== /** ============ CHECK FOR PRIME ============= */ int check_prime( int a) { int c; if ( a == 2 || a == 3 || a == 5 || a ==7) //check if the number is 2 { return 1; } else if (a % 2 == 0 || a % 3 == 0 || a % 5 == 0 || a % 7 == 0) //check if the number is even { return 0; } else //for odd numbers, check if they are prime { for (c = 11; c { if (a%c == 0) return 0; } if ( c == a) return 1; } } /** ============ END CHECK PRIME============== */ /** ============ THREAD ===================== */ DWORD WINAPI primer(LPVOID lpParam) { prArray& dan = *(prArray*)lpParam; /*working initialization */ dan.pTest = (dan.pEnd - dan.pStart); // initialize the array to "0" for ( int i = 0; i { dan.tArray[i] = 0; } int b = 0; for ( int lp = dan.pStart; lp { int result3 = check_prime(lp); if (result3 == 1) { dan.tArray[b] = lp; b++; } } } hope this will help you..... Good Luck

thread to each that will calc the prime numbers >100