View source for SE250:lab-3:shua066

==task 1==
===code===
 int main(){
     clock_t t0=clock();
     ArrayList xs;
     arraylist_init(&xs);
     int i;
     for(i=1; i<10000000; i++){
         arraylist_push(&xs, 10);
     }
     printf("%ld\n",clock()-t0);
     return 0;
 }

===result=== 
 452 436 452 436 437 421
the average is 440.8
==task 2==
change the factor "*2.0"
                                                 average
 "*3.0"   359 342 390 328 358 327 327 359 342      348
 "*4.0"   265 359 358 342 312 343 311 311 327      325.3
 "*5.0"   343 343 389 342 327 390 358 326 359      353
 "*6.0"   327 343 327 311 327 358 311 312 265      320
 "*7.0"   296 311 343 327 296 280 312 280 359      311.5
 "*8.0"   266 311 296 265 249 327 311 389 343      306
 "*9.0"   327 296 280 296 311 280 343 296 327      306
when the factor is bigger , the time takes shorter, and when the factor grow up to 6.0 the time change is shorter shorter.
==task 3==
change the restore value of ''' ARRAYLIST_MIN_ALLOC '''

'''ARRAYLIST_MIN_ALLOC 1'''
 468 421 389 421 405 389    ave is 415.5
'''ARRAYLIST_MIN_ALLOC 3'''
 389 374 405 374 343 358    ave is 373
'''ARRAYLIST_MIN_ALLOC 6'''
 342 374 359 374 327 358    ave is 355
'''ARRAYLIST_MIN_ALLOC 16''' 
 ave is 348 (num from task 1 above)
'''ARRAYLIST_MIN_ALLOC 30'''
 389 406 374 359 389 406    ave is 387
'''ARRAYLIST_MIN_ALLOC 60'''
 359 343 359 390 343 390    ave is 364
'''ARRAYLIST_MIN_ALLOC 100'''
 374 374 358 343 326 343    ave is 353
'''ARRAYLIST_MIN_ALLOC 1000'''
 342 405 359 375 358 405    ave is 374
'''ARRAYLIST_MIN_ALLOC 10000'''
 327 280 311 343 375 374    ave is 335
'''ARRAYLIST_MIN_ALLOC 1000000'''
 343 358 312 358 405 297    ave is 345.5
'''ARRAYLIST_MIN_ALLOC 100000000'''
 265 281 280 280 249 311    ave is 277
'''ARRAYLIST_MIN_ALLOC 1000000000'''
 result is error , number is too big
'''ARRAYLIST_MIN_ALLOC 10000000000'''
 comeout lots of warnings
==task 4==
===code===
 int main(){
     clock_t t0=clock();
     ArrayList xs;
     arraylist_init(&xs);
     ensure_capacity(&xs,10000000);
     int i;
     for(i=1; i<10000000; i++){
         arraylist_push(&xs, 10);
     }
     printf("%ld\n",clock()-t0);
     return 0;
 }
===result===
 312 296 342 343 264 280 265 
 average is 300

==task 5==
change the '''arraylist_put''' replay"*2"with adding some numbers

+1000 n=1000000 push=10
 31 31 15 30 46 31
 average is 30.6
+10000 n=1000000 push=10
 46 47 46 51 31 15
 average is 39.3
+100000 n=1000000 push=10
 31 46 31 15 30 16
 average is 28.2
+1000000 n=1000000 push=10
 31 15 31 15 63 31
 average is 31
+5000000 n=1000000 push=10
 15 30 31 31 46 15
 average is 28

when the adding the number is bigger , the time is change up and down ,and in adding the same number(like "+1000000 n=1000000 push=10"),time is change as well, sometimes is only 15 ,and sometimes is 30, but ever sometimes it change to 63 as well , so strange.

==task 6==
===code===
 int main(){
     clock_t t0=clock();
     ArrayList xs;
     arraylist_init(&xs);
     int i;
     for(i=1; i<10000000; i++){
         arraylist_put(&xs, 10,0);
     }
     printf("%ld\n",clock()-t0);
     return 0;
 }

===result===
it takes very very long time to finish it .
so , i  change the number of n to 100000
 3260 3198 3182 3135 3322
 average is 3219