Crivello di Eratostene con calcolo pi

#include <stdio.h>
#include <time.h>

#define RANGE 10000u

typedef unsigned char uint_8;

uint_8 composite[RANGE];

int main(void) {
    clock_t Ticks, TicksDelta;
    unsigned int Sec;
    unsigned int Milli;

    unsigned int i;
    unsigned int j=2;
    unsigned int pi=0;
    unsigned int pr=0;
    unsigned int ScopeMax;
    unsigned int ScopeMaxMax;


    for(j=0; j<RANGE; ++j) {
        composite[j]=0;
    }
    ScopeMax    = RANGE/2;
    ScopeMaxMax= ScopeMax;

    printf("\nPress enter to start\n");
    getchar();
    printf("\nComputing...\n");
    Ticks = clock();
    j=2;
    while(j<ScopeMaxMax) {
    pr=j;
        for (i=2; i<=ScopeMax; ++i) { pr=pr+j; composite[pr-1]=1;}

        ++j;
        ScopeMax=RANGE/j;
     }
    TicksDelta = clock() - Ticks;
    Sec = (unsigned short) (TicksDelta / CLOCKS_PER_SEC);
    Milli = ((TicksDelta % CLOCKS_PER_SEC) * 1000) / CLOCKS_PER_SEC;
    printf ("Time used: %u.%03u seconds = %u ticks\n", Sec, Milli, (unsigned short) TicksDelta);

    printf("Press enter to print the prime numbers\n");
    getchar();
    printf("\n");
    composite[0]=1;
    composite[1]=0;
    for(i=0; i<RANGE; ++i) {
        if(composite[i]==0) {
        ++pi;
            printf(" %u ", i+1);
        }
    }
    printf("\nPi = %u", pi);

    return 0;
}