SPOJ PRIME1 - tweaked code by BLUEPIXY

#include <stdio.h>     /* SPOJ PRIME1 -- tweaked from code by BLUEPIXY  */
#include <stdlib.h>    /* at http://stackoverflow.com/a/18041372/849891 */

int main(void){
    int k,m[10],n[10],prime[100001],i0,i,j,s,tmp,d;
    scanf("%d ",&k);
    if( k>10) {exit(1);}  /* breach of contract */
    for(i=0;i<k;i++){
        scanf("%d %d",&m[i],&n[i]);
        if( n-m > 100000) {exit(2);}
    for(s=0;s<k;s++){
        if(3>m[s]){i0=3;} else {i0=m[s];}
        tmp = (i0&1) ? 1 : (++i0);
        for( i=i0;i<= n[s];i+=2){
            prime[ i-m[s] ] = 1; /* mark all odds as prime */
        }
        for(i=3, d=6; (j=i*i)<= n[s]; i+=2, d+=4){
            if( j < i0 ) {j += ((i0-j+d-1)/d) * d;}
            for( ; j<=n[s]; j+=d){
                prime[ j-m[s] ] = 0;} /* mark mults of odds as non-prime */
        }
        if(2 >= m[s]) {printf( "2\n");}
        for(i=i0;i<=n[s];i+=2){
            if(prime[i-m[s]]){
                printf("%d\n",i);}}
        printf("\n");
    }
    return 0;
}