SE250:lab-3:jhor053
Lab 2
Task 1
Here is my code:
#include <stdlib.h>
#include <time.h>
#include <stdio.h>
#include "arraylist.h"
int main (){
ArrayList AL;
double start, end, diff;
int ntimes = 10000000;
int pushed = 1;
int i;
arraylist_init(&AL);
start = clock();
for(i = 0; i < ntimes; i++){
arraylist_push(&AL, pushed);
}
end = clock();
diff = (end - start) / CLOCKS_PER_SEC;
printf("Difference in time for %d elements is: %f \n", ntimes, diff );
return 0;
}
In my code ntimes being n (10000000) and i was pushing the value pushed which was an int of value 1.
My result was:
Difference in time for 1000000 elements is: 0.198000 Difference in time for 2000000 elements is: 0.293000 Difference in time for 3000000 elements is: 0.448000 Difference in time for 4000000 elements is: 0.614000 Difference in time for 5000000 elements is: 0.767000 Difference in time for 6000000 elements is: 0.892000 Difference in time for 7000000 elements is: 1.133000 Difference in time for 8000000 elements is: 1.173000 Difference in time for 9000000 elements is: 1.392000 Difference in time for 10000000 elements is: 1.802000
Seemed alright but it didn't quite take into account the for loop.
Task 2
I modified my ocde further to automate the task of changing values for a set value in arraylist_put
int main (){
ArrayList AL;
double start, end, diff;
int ntimes = 10000000;
int pushed = 1;
int i;
for(ntimes = 1000000; ntimes <= 10000000; ntimes += 1000000){
arraylist_init(&AL);
start = clock();
for(i = 0; i < ntimes; i++){
arraylist_push(&AL, pushed);
}
end = clock();
diff = (end - start) / CLOCKS_PER_SEC;
printf("Difference in time for %d elements is: %f \n", ntimes, diff );
arraylist_clear(&AL);
}
return 0;
}
My result now is for * 3 factor
Difference in time for 1000000 elements is: 0.172000 Difference in time for 2000000 elements is: 0.276000 Difference in time for 3000000 elements is: 0.447000 Difference in time for 4000000 elements is: 0.592000 Difference in time for 5000000 elements is: 0.738000 Difference in time for 6000000 elements is: 0.950000 Difference in time for 7000000 elements is: 0.975000 Difference in time for 8000000 elements is: 1.106000 Difference in time for 9000000 elements is: 1.348000 Difference in time for 10000000 elements is: 1.478000
My result now is for the * 4 factor
Difference in time for 1000000 elements is: 0.222000 Difference in time for 2000000 elements is: 0.313000 Difference in time for 3000000 elements is: 0.409000 Difference in time for 4000000 elements is: 0.674000 Difference in time for 5000000 elements is: 0.872000 Difference in time for 6000000 elements is: 0.924000 Difference in time for 7000000 elements is: 1.012000 Difference in time for 8000000 elements is: 1.142000 Difference in time for 9000000 elements is: 1.244000 Difference in time for 10000000 elements is: 1.393000
My result now is for the * 5 factor
Difference in time for 1000000 elements is: 0.154000 Difference in time for 2000000 elements is: 0.290000 Difference in time for 3000000 elements is: 0.420000 Difference in time for 4000000 elements is: 0.578000 Difference in time for 5000000 elements is: 0.759000 Difference in time for 6000000 elements is: 0.880000 Difference in time for 7000000 elements is: 1.135000 Difference in time for 8000000 elements is: 1.336000 Difference in time for 9000000 elements is: 1.500000 Difference in time for 10000000 elements is: 1.708000
Performance seems to change as you greatly increase the amount of memory to copy accross ie a factor of 10 or 20 crashes it for 9 million values.
Task 3
With ARRAYLIST_MIN_ALLOC set to 32:
Difference in time for 1000000 elements is: 0.177000 Difference in time for 2000000 elements is: 0.342000 Difference in time for 3000000 elements is: 0.432000 Difference in time for 4000000 elements is: 0.690000 Difference in time for 5000000 elements is: 0.760000 Difference in time for 6000000 elements is: 0.955000 Difference in time for 7000000 elements is: 1.055000 Difference in time for 8000000 elements is: 1.251000 Difference in time for 9000000 elements is: 1.385000 Difference in time for 10000000 elements is: 1.462000
With ARRAYLIST_MIN_ALLOC set to 64:
Difference in time for 1000000 elements is: 0.164000 Difference in time for 2000000 elements is: 0.302000 Difference in time for 3000000 elements is: 0.560000 Difference in time for 4000000 elements is: 0.657000 Difference in time for 5000000 elements is: 0.817000 Difference in time for 6000000 elements is: 0.944000 Difference in time for 7000000 elements is: 0.987000 Difference in time for 8000000 elements is: 1.201000 Difference in time for 9000000 elements is: 1.316000 Difference in time for 10000000 elements is: 1.487000
With ARRAYLIST_MIN_ALLOC set to 128:
Difference in time for 1000000 elements is: 0.165000 Difference in time for 2000000 elements is: 0.289000 Difference in time for 3000000 elements is: 0.519000 Difference in time for 4000000 elements is: 0.673000 Difference in time for 5000000 elements is: 0.909000 Difference in time for 6000000 elements is: 1.065000 Difference in time for 7000000 elements is: 1.125000 Difference in time for 8000000 elements is: 1.172000 Difference in time for 9000000 elements is: 1.344000 Difference in time for 10000000 elements is: 1.451000
Well doing it in relatively small values seemed useless so I went for a million default and was quicker
Difference in time for 1000000 elements is: 0.156000 Difference in time for 2000000 elements is: 0.273000 Difference in time for 3000000 elements is: 0.412000 Difference in time for 4000000 elements is: 0.659000 Difference in time for 5000000 elements is: 0.816000 Difference in time for 6000000 elements is: 0.875000 Difference in time for 7000000 elements is: 0.986000 Difference in time for 8000000 elements is: 1.118000 Difference in time for 9000000 elements is: 1.323000 Difference in time for 10000000 elements is: 1.454000
Increasing min alloc insanely made it far faster for the early values as it didn't have allocate any more memory.
Task 4
Using required capacity I passed ntimes + 1 Getting:
Difference in time for 1000000 elements is: 0.147000 Difference in time for 2000000 elements is: 0.281000 Difference in time for 3000000 elements is: 0.387000 Difference in time for 4000000 elements is: 0.594000 Difference in time for 5000000 elements is: 0.713000 Difference in time for 6000000 elements is: 0.865000 Difference in time for 7000000 elements is: 0.947000 Difference in time for 8000000 elements is: 1.097000 Difference in time for 9000000 elements is: 1.151000 Difference in time for 10000000 elements is: 1.278000
Which is significantly faster as it won't take the time to allocate memory.
Task 5
Started off with n being 10000 and going up in 10000 as it was too quick either wise
Difference in time for 10000 elements is: 0.002000 Difference in time for 20000 elements is: 0.004000 Difference in time for 30000 elements is: 0.004000 Difference in time for 40000 elements is: 0.006000 Difference in time for 50000 elements is: 0.008000 Difference in time for 60000 elements is: 0.008000 Difference in time for 70000 elements is: 0.008000 Difference in time for 80000 elements is: 0.011000 Difference in time for 90000 elements is: 0.012000 Difference in time for 100000 elements is: 0.022000