SE250:lab-3:dcho040
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Q1
Codes
#include <stdio.h>
#include "arraylist.h"
#define add_time 10000000
#define add_value 2147483647
#define number_trial 10
int main() {
ArrayList xs;
arraylist_init(&xs);
int i,j;
int time_total = 0;
double time_avg;
for (i = 0; i < number_trial; i++) {
clock_t t0 = clock();
for (j = 0; j < add_time; j++) {
arraylist_push(&xs, add_value);
}
clock_t t1 = clock();
time_total += t1 - t0;
}
time_avg = (double)time_total / number_trial;
printf("put %d, %ld times took average %.2lf s", add_value, add_time, time_avg);
return 0;
}
Prediction
- (wrong)Both The number of times saving and The value saved affect to the time
Results 1 (Vista in G-Lab)
put 1, 100000 times took average 4.60 s put 1, 1000000 times took average 45.20 s put 1, 10000000 times took average 410.30 s put 1, 100000000 times : error assertion "alist->arr != (element_t*)0" faild: file "arraylist.c", line 40 10 [sig] lab3_1 3496 h:\soft250lab\lab3\lab3_1.exe: *** fatal error - called with threadlist_ix -1 Hangup
Results 2 (Vista in G-Lab)
put 2147483647, 100000 times took average 4.70 s put 2147483647, 1000000 times took average 45.20 s put 2147483647, 10000000 times took average 427.40 s put 2147483647, 100000000 times : error assertion "alist->arr != (element_t*)0" faild: file "arraylist.c", line 40 10 [sig] lab3_1 3496 h:\soft250lab\lab3\lab3_1.exe: *** fatal error - called with threadlist_ix -1 Hangup
Discussion
- Total time would proportion to the number of times saving the value. - The value saved would not affect to the total time - No idea with the error when input the values 100,000,000 times
Q2
Prediction
- (partly true)The time decreses while (*2) increases because of less memory relocating occured
Results 1 (Vista(AMD) at home)
put 2147483647, 10,000,000 times
*2 : 535.00 s
*4 : 496.00 s
*6 : 461.70 s
*8 : 466.40 s
*10 : 449.20 s
*12 : assertion "alist->arr != (element_t*)0" failed: file "arraylist.c", line 40
15 [sig] lab3_1 4032 _cygtls:: handle_exceptions: Error while dumping state (probably corrupted stack)
Segmentation fault (core dumped)
*14 : 449.20 s
*16 : 449.20 s
*18 : assertion "alist->arr != (element_t*)0" failed: file "arraylist.c", line 40
14 [sig] lab3_1 4024 _cygtls:: handle_exceptions: Error while dumping state (probably corrupted stack)
Segmentation fault (core dumped)
*20 : assertion "alist->arr != (element_t*)0" failed: file "arraylist.c", line 40
12 [sig] lab3_1 2968 _cygtls:: handle_exceptions: Error while dumping state (probably corrupted stack)
Segmentation fault (core dumped)
*22 : assertion "alist->arr != (element_t*)0" failed: file "arraylist.c", line 40
12 [sig] lab3_1 876 _cygtls:: handle_exceptions: Error while dumping state (probably corrupted stack)
Segmentation fault (core dumped)
*24 : 447.60 s
Results 2 (Vista(AMD) at home)
put 2147483647, 1,000,000 times *2 : 53.00 s *4 : 48.30 s *6 : 45.10 s *8 : 48.30 s *10 : 43.60 s *12 : 46.70 s *14 : 49.80 s *16 : 46.70 s *18 : 43.70 s *20 : 45.10 s *22 : 43.60 s
Discussion
- The time reduces while (*2) in arraylist_put increases, but is stable from around (*6) - large mount of inputs(10,000,000) shows error in some cases
Q3
Prediction
-(Not quite right)Maybe the results show random times.
Results 1 (Vista(AMD) at home)
Increase ARRAYLIST_MIN_ALLOC put 2147483647, 10,000,000 times 16 : 538.10 s 160 : 549.00 s 1600 : 508.40 s 16000 : 516.20 s 160000 : 552.20 s 1600000 : 503.80 s 16000000 : 517.80 s
Results 2 (Vista(AMD) at home)
Increase ARRAYLIST_MIN_ALLOC put 2147483647, 1,000,000 times 16 : 54.50 s 32 : 53.00 s 48 : 51.50 s 64 : 54.50 s 80 : 49.80 s 96 : 51.40 s 112 : 53.00 s 128 : 54.50 s 144 : 54.50 s 160 : 49.90 s
Results 3 (Vista(AMD) at home)
Increase ARRAYLIST_MIN_ALLOC put 2147483647, 1,000,000 times 16 : 52.90 s 26 : 49.90 s 36 : 54.50 s 46 : 49.90 s 56 : 59.90 s 66 : 54.50 s 47 : 48.20 s 17 : 54.60 s 27 : 51.40 s 37 : 56.10 s 47 : 51.50 s 57 : 51.40 s 67 : 54.10 s 48 : 48.40 s 18 : 57.60 s 28 : 53.00 s 38 : 56.10 s 48 : 49.90 s 58 : 49.90 s 68 : 56.10 s 49 : 49.90 s 19 : 57.60 s 29 : 53.00 s 39 : 49.90 s 49 : 49.80 s 59 : 51.50 s 69 : 54.60 s 20 : 49.90 s 30 : 52.90 s 40 : 49.80 s 50 : 51.40 s 60 : 53.00 s 70 : 54.60 s 21 : 48.40 s 31 : 54.50 s 41 : 49.90 s 51 : 51.50 s 61 : 53.00 s 71 : 56.10 s 22 : 49.90 s 32 : 54.50 s 42 : 51.40 s 52 : 48.30 s 62 : 51.40 s 72 : 56.10 s 23 : 51.50 s 33 : 56.10 s 43 : 49.90 s 53 : 53.00 s 63 : 53.10 s 73 : 53.00 s 24 : 51.40 s 34 : 54.50 s 44 : 49.90 s 54 : 52.90 s 64 : 51.50 s 74 : 54.50 s 25 : 51.40 s 35 : 54.50 s 45 : 48.30 s 55 : 52.90 s 65 : 54.50 s 75 : 48.20 s
Discussion
- Generally times increases while ARRAYLIST_MIN_ALLOC increases, but some points the time drops.
Q4
Codes
#include <stdio.h>
#include "arraylist.h"
#define add_time 10000000
#define add_value 2147483647
#define number_trial 10
int main() {
ArrayList xs;
arraylist_init(&xs);
int i,j;
int time_total = 0;
double time_avg;
ensure_capacity(&xs, add_time); // pre-allocate the meximum expected size of the array
for (i = 0; i < number_trial; i++) {
clock_t t0 = clock();
for (j = 0; j < add_time; j++) {
arraylist_push(&xs, add_value);
}
clock_t t1 = clock();
time_total += t1 - t0;
}
time_avg = (double)time_total / number_trial;
printf("put %d, %ld times took average %.2lf s", add_value, add_time, time_avg);
return 0;
}
Prediction
- (right)pre-allocate the meximum expected size of the array saves the time.
Results 1 (Vista(AMD) at home)
experiment1 put 2147483647, 100,000 times took average 32.80 s put 2147483647, 1,000,000 times took average 2194.90 s put 2147483647, 10,000,000 times took average 202227.10 s
Results 2 (Vista(AMD) at home)
pre-allocate the meximum expected size of the array put 2147483647, 100,000 times took average 29.70 s put 2147483647, 1,000,000 times took average 2148.10 s put 2147483647, 10,000,000 times took average 203534.40 s
Discussion
- There is time saving from pre-allocating the meximum expected size of the array
Q5
Prediction
- (+1000) took more time than (*2) because (+1000) does more replacing than (* 2)
Results 1 (Vista(AMD) at home)
(*2) in arrylist_put put 2147483647, 100,000 times took average 4.60 s put 2147483647, 200,000 times took average 9.30 s put 2147483647, 300,000 times took average 15.60 s put 2147483647, 400,000 times took average 20.20 s put 2147483647, 500,000 times took average 26.40 s put 2147483647, 600,000 times took average 31.20 s put 2147483647, 700,000 times took average 35.80 s put 2147483647, 800,000 times took average 38.90 s put 2147483647, 900,000 times took average 50.00 s put 2147483647, 1000,000 times took average 53.00 s
Results 2 (Vista(AMD) at home)
(+2000) in arrylist_put put 2147483647, 100,000 times took average 23.50 s put 2147483647, 200,000 times took average 87.30 s put 2147483647, 300,000 times took average 193.40 s put 2147483647, 400,000 times took average 352.40 s put 2147483647, 500,000 times took average 542.90 s put 2147483647, 600,000 times took average 773.70 s put 2147483647, 700,000 times took average 1040.50 s put 2147483647, 800,000 times took average 1358.70 s put 2147483647, 900,000 times took average 1733.10 s put 2147483647, 1000,000 times took average 2157.40 s
Discussion
- As put values more, (+1000) needs huge mount of times to precess
Q6
codes
#include <stdio.h>
#include "arraylist.h"
#define add_time 10000
#define add_value 2147483647
#define number_trial 10
int main() {
ArrayList xs;
arraylist_init(&xs);
int i,j;
int time_total = 0;
double time_avg;
for (i = 0; i < number_trial; i++) {
clock_t t0 = clock();
for (j = 0; j < add_time; j++) {
arraylist_put(&xs, add_value, 0);
}
clock_t t1 = clock();
time_total += t1 - t0;
}
time_avg = (double)time_total / number_trial;
printf("put %d, %ld times took average %.2lf s", add_value, add_time, time_avg);
return 0;
}
Prediction
- (true) Arraylist_put with index 0 is much slower than experiment 1
Results 1 (Vista(AMD) at home)
Arraylist_put with index 0 put 2147483647, 1,000 times took average 1.50 s put 2147483647, 2,000 times took average 14.00 s put 2147483647, 3,000 times took average 45.20 s put 2147483647, 4,000 times took average 93.60 s put 2147483647, 5,000 times took average 154.40 s put 2147483647, 6,000 times took average 229.30 s put 2147483647, 7,000 times took average 312.00 s put 2147483647, 8,000 times took average 414.90 s put 2147483647, 9,000 times took average 517.80 s put 2147483647, 10,000 times took average 655.20 s
Results 2 (Vista(AMD) at home)
experiment 1 put 2147483647, 10,000 times took average 1.50 s
Discussion
As expected, Arraylist_put with index 0 is much slower than experiment 1