too many for loops??

[predator887]

hey.. im having a problem with my code...

its quite a long script and this is a pretty big extract but the main part im having the issue with is the inner most nested for loop

for(i=0;i<N_gnc2;i++){

    for(l=0;l<N_gnc1;l++){                  

absolute3[l]=abs(index_gnc2[index_gncthistag[i]]-index_TS2[index_TSthistag[l]]);
    
    }
}

if i set N_gnc1 to 10 or 100 the code runs but if i set it to the correct value which is 109727 then it appears to run indefinetly

here is the larger part of the script that the code is a part of, important variables are

end_i=462154
n_TS = 109727;
n_TN = 7;
lengthtypeofTT = 5;

i apologise if i made any mistakes posting hear... im still a beginner on these forums and with programming in general.

int N_gnc1;
int N_gnc2;

int *index_gnctoTS;    
index_gnctoTS = (int *)malloc(end_i * sizeof(int));

int *index_TSthistag;    
index_TSthistag = (int *)malloc(end_i * sizeof(int));

int *index_gncthistag;    
index_gncthistag = (int *)malloc(end_i * sizeof(int));

int *absolute3;    
absolute3 = (int *)malloc(end_i * sizeof(int));

int n_TN;

n_TS = elnum_index_TS2;
n_TN = elnum5;
lengthtypeofTT;

n=0;
m=0;

printf("n_TS = %d\n", n_TS);
printf("n_TN = %d\n", n_TN);
printf("end_i = %d\n", end_i);
printf("lengthtypeofTT = %d\n", lengthtypeofTT);

for(i=0;i<n_TS;i++){
    index_gnctoTS[i]=0;
}

for(j=0;j<n_TN;j++){
    for(k=0;k<lengthtypeofTT;k++){
        for(i=0;i<n_TS;i++){
            if( (time_tag2[index_TS2[i]]==typeofTT[k]) && (node_id2[index_TS2[i]]==node_type[j]) ){
                index_TSthistag[m]=i;
                m=m+1;
            }
        }
        N_gnc1=m;

        for(i=0;i<n_TS;i++){
            if( (time_tag2[index_gnc2[i]]==typeofTT[k]) && (node_id2[index_gnc2[i]]==node_type[j]) ){
                index_gncthistag[n]=i;
                n=n+1;
            }
        }
        N_gnc2=n;
        for(i=0;i<N_gnc2;i++){
            for(l=0;l<N_gnc1;l++){
                 absolute3[l]=abs(index_gnc2[index_gncthistag[i]]-index_TS2[index_TSthistag[l]]);

            }
        }
    }
}

[predator887]

oh and if its useful here is the Matlab code that im trying to convert to C

n_TS=length(find(index_TS));
    index_gnctoTS=zeros(n_TS,1);
    delta_index=0;
    n_TN=length(typeofnode);
    for j=1:n_TN
        for k=1:length(typeofTT)
            index_TSthistag=find((time_tag(index_TS)==typeofTT(k))&(node_id(index_TS)==typeofnode(j)));
            index_gncthistag=find((time_tag(index_gnc)==typeofTT(k))&(node_id(index_gnc)==typeofnode(j)));
            N_gnc=length(index_gncthistag);
            for i=1:N_gnc
                [dummy,index_min]=min(abs(index_gnc(index_gncthistag(i))-index_TS(index_TSthistag)));    
                index_gnctoTS(index_gncthistag(i))=index_TS(index_TSthistag(index_min));
                delta_index=max(dummy,delta_index);
            end
        end
    end

[iMalc]

What makes you say it runs indefinitely? It should take on the order of 1000 times longer, and if it was originally taking a second then you can expect it to take several minutes.
What compiler are you using? Not a 16-bit one by chance?

[predator887]

thanks for the reply, and sorry for my late reply ... i put it aside for a few days and did other coding...

im using Netbeans with Cygwin... i dont know if thats a 16bit compiler... haha sry if im a bit of a programming virgin

when i say indenfinite i left it for about 8-11 minutes and it still hadnt finished... i assumed it wasnt going to stop.... anyway if its gonna take more than a minute or 2 to run this then thats far too long and ill have to find some other ideas