2019.05.29 / 24:51
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ÀÚ¹Ù¿¡¼ ÀÛ¼ºÇÑ ¸Þ¼Òµå³ª ¾Ë°í¸®ÁòÀÇ ¼Óµµ¸¦ ¾Ë¾Æº¸°í ½ÍÀ» ¶§ ÀÌ¿ëÇÏ´Â ¸Þ¼Òµå¸¦ ¼Ò°³ÇÑ´Ù.
C¾ð¾î ¼Óµµ ÃøÁ¤Àº ÀÌ ±ÛÀ» Âü°íÇÏ±æ ¹Ù¶õ´Ù.
¼ÓµµÃøÁ¤¿¡ »ç¿ëµÇ´Â ¸Þ¼Òµå´Â SystemŬ·¡½º¿¡ ¼±¾ðµÈ currentTimeMillis()¸Þ¼ÒµåÀÌ´Ù.
»ç¿ë ¹æ¹ýÀº ¾Æ·¡¿Í °°´Ù.
»ç¿ë ¹æ¹ý :
pubic class Main{
public static void main(String []args){
long st = System.currentTimeMillis();
//¼Óµµ ÃøÁ¤ÇÒ ¸Þ¼Òµå
long et = System.currentTimeMillis();
System.out.println((et - st)+" ms");
}
}
ÀÚ·áÇüÀÌ longÀÓÀ» ¸í½ÉÇϸç C¿Í µ¿ÀÏÇÏ°Ô ¹öºí¼ÒÆ® vs Äü ¼ÒÆ®·Î ºñ±³¸¦ ÇØ º¸ÀÚ
import java.util.Arrays;
public class Main {
public static void main(String[] args) {
int i, a[] = new int[10000], b[] = new int[10000];
//1~10000»çÀÌ ·£´ý»ý¼ºÇØ a[i]¿Í b[i]¿¡ µ¿ÀÏÇÏ°Ô ´ëÀÔ
for(i=0;i<10000;i++){
a[i] = (int)(Math.random()*10000)+1;
b[i] = a[i];
}
//¹öºíÁ¤·Ä ½Ã°£ÃøÁ¤
long st1 = System.currentTimeMillis();
bubbleSort(a);
long et1 = System.currentTimeMillis();
//Äü Á¤·Ä ½Ã°£ÃøÁ¤
long st2 = System.currentTimeMillis();
Arrays.sort(b); //Äü¼ÒÆ®´Â ±×³É ÀÌ·±½ÄÀ¸·Î ÇÏ¸é µÊ(Ãâ·ÂÀº ´Ù¸¥¹æ½ÄÀÌ´Ï ÁÖÀÇ!)
long et2 = System.currentTimeMillis();
System.out.println("¹öºí¼ÒÆ® ¼Óµµ : "+(et1 - st1)+" ms");
System.out.println("Äü ¼ÒÆ® ¼Óµµ : "+(et2 - st2)+" ms");
}
public static void bubbleSort(int a[]){ //¹öºíÁ¤·Ä ¸Þ¼Òµå
for (int i = 0; i < 9999; i++)
for (int j = 0; j < 9999; j++)
if (a[j] > a[j + 1]) {
int tmp = a[j];
a[j] = a[j + 1];
a[j + 1] = tmp;
}
}
}
°á°ú´Â ¾Æ·¡¿Í °°´Ù.
ÀÌ ¿ª½Ã Á¤·Ä ÇÔ¼öµéÀ» °ÅÀÇ ³¯¸²À¸·Î »ç¿ëÇϱä Çߴµ¥ ¾Æ¹«Æ° ¸ñÀûÀº ½Ã°£ÃøÁ¤ ¸Þ¼Òµå¿¡ ´ëÇØ ¾Ë¾Æº¸´Â °ÍÀÌ´Ï currentTimeMillis() »ç¿ë¹ý¿¡ ÁýÁßÇϵµ·Ï ÇÏÀÚ.