10-3_ArrayOf20Handling.java

/*_à Äàí ìàññèâ èç 20 öåëûõ ÷èñåë ñî çíà÷åíèÿìè îò 1 äî 20. Íåîáõîäèìî: 

1) íàïèñàòü ôóíêöèþ, ðàçáðàñûâàþùóþ ýëåìåíòû ìàññèâà ïðîèçâîëüíûì îáðàçîì; 

2) ñîçäàòü ñëó÷àéíîå ÷èñëî èç òîãî æå äèàïàçîíà è íàéòè ïîçèöèþ ýòîãî ñëó÷àéíîãî ÷èñëà â ìàññèâå; 

3) îòñîðòèðîâàòü ýëåìåíòû ìàññèâà, íàõîäÿùèåñÿ ñëåâà îò íàéäåííîé ïîçèöèè ïî óáûâàíèþ, à ýëåìåíòû
 ìàññèâà, íàõîäÿùèåñÿ ñïðàâà îò íàéäåííîé ïîçèöèè ïî âîçðàñòàíèþ. 
*/

package lesson10;

//import java.lang.reflect.Array;
import java.util.Random;

public class ArrayOf20Handling {
	
	static Random random;
	
	//_à Ìåòîä ðàçáðàñûâàåò ýëåìåíòû ìàññèâà
	public static void flyElements (Integer[] array) {
		System.out.println("Ýëåìåíòû ðàçáðîñàíû:");
		
		for (int i=0; i<array.length; i++) {	//_à Îáùèé ïðîõîä ïî ìàññèâó
						
			int k = random.nextInt(20)+1;	//_à Ïðîèçâîëüíîå ÷èñëî
			int x = array[i];	//_à   õ - ïîòî÷íûé ýëåìåíò ìàññèâà
								
			for (int j=i+1; j<array.length; j++) {	//_à Ïðîõîä ñïðàâà îò ïðîéäåíûõ ýëåìåíòîâ
							
				if (k==j) {		//_à Ñîïîñòàâëÿåì ñëó÷àéíîå ÷èñëî ñ ïîðÿäêîâûì íîìåðîì ìàññèâà 
					
					//_à Ìåíÿåì ìåñòàìè ýëåìåíòû i-òûé ñ ðåíäîìíûì
					x =array[j];
					array[k] = array[i];
					array[i] = x;
						
					break;	//_à äàëüøå íå íóæíî, èáî ïîâòîð k==j áóäåò òîëüêî 1 ðàç
				}
			}
			System.out.print(x + " ");	
		}
	}
	
	public static void main(String[] args) {
		
		random = new Random();
		
		//_à Ìàññèâ Integer (öåëûå ÷èñëà îò 1 äî 20)
		//Integer[] array = {1, 17, 2, 13, 3, 4, 20, 18, 16, 5, 12, 6, 7, 11, 19, 8, 9, 10, 14, 15};
		Integer[] array = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20};
		
		//System.out.println(array.length);	//_à Äëèíà ìàññèâà
		
		//_à Ïîêàç ìàññèâà
		System.out.println("Âõîäíîé ìàññèâ:");
		for (int i=0; i<array.length; i++) { 
			System.out.print(array[i] + " ");
		}
		
		System.out.println();
		System.out.println();
		
		//_à Ðàçáðàñûâàåì ýëåìåíòû
		flyElements(array);
		
		System.out.println();
		System.out.println();
		
		//
			//_à Ñëó÷àéíîå ÷èñëî èç äèàïàçîíà [1; 20]
			int randomNumber = random.nextInt(20)+1;
			System.out.println("Ñëó÷àéíîå ÷èñëî = " + randomNumber);
			
			//_à Âûäåëÿåì ÷èñëî â ìàññèâå äëÿ íàãëÿäíîñòè
			for (int i=0; i<array.length; i++) { 
				if (array[i] == randomNumber) {
					System.out.print("|" + array[i] + "| ");
				} else System.out.print(array[i] + " "); 	
			}
			
			System.out.println();
			
			//_à Ïîçèöèÿ ñëó÷àéíîãî ÷èñëà â ìàññèâå
			int randomIndex=0;
			for (int i=0; i<array.length; i++) { 
				if (array[i] == randomNumber) {
					randomIndex = i;
					System.out.println("Ïîðÿêäîâûé íîìåð ñëó÷àéíîãî ÷èñëà =  " + randomIndex);
					break;
				}
			}
		//
		
			System.out.println();
				
			
		//_à Ñîðòèðîâêà ëåâîé è ïðàâîé ÷àñòè îò randomNumber
			//_à Ñëåâà îò randomNumber - ïî óáûâàíèþ 	
			for (int i=0; i<randomIndex; i++) {
				int k = i;
				int x = array[i];
				
				for (int j=i+1; j<randomIndex; j++) {
					if (array[j] > x) {
						k = j;
						x = array[j];
						array[k] = array[i];
						array[i]  =  x;
					}
				}
				
			}
					
			//_à Ñïðàâà îò randomNumber - ïî âîçðàñòàíèþ 	
			for (int i=randomIndex+1; i<array.length; i++) {
				int k = i;
				int x = array[i];
				
				for (int j=i+1; j<array.length; j++) {
					if (array[j] < x) {
						k = j;
						x = array[j];
						array[k] = array[i];
						array[i]  =  x;
					}
				}
			}

			
			//_à Âûâîä ìàññèâà ïîñëå ñîðòèðîâîê
			System.out.println("Ïîñëå ñîðòèðîâîê:");
			
			 for(int i=0; i<array.length; i++){
				 if (array[i] == randomNumber) {
					 System.out.print("|" + array[i] + "| ");
				 }
			     else System.out.print(array[i]+" ");
			 }
	}

}