알고리즘2 (버블정렬(C언어), 선택정렬(Python), 삽입정렬(Java))

Bubble Sort 1 단계

 

 

 

 

 

Bubble Sort 2단계

 

Bubble Sort 3단계

 

 

 

 

Bubble Sort 실제 코드 구현

 

 

 

Bubble Sort

#include <stdio.h>

void swap(int* a, int* b) {
	int temp;
	temp = *a;
	*a = *b;
	*b = temp;
}

int Data[5] = { 3, 2, 5, 4, 1 };
int main()
{
	int howmany = sizeof(Data) / sizeof(Data[0]);
	for (int until = howmany - 1; until >= 0; until--)
		for (int now = 0; now < until; now++)
			if (Data[now] > Data[now + 1])
				swap(&Data[now], &Data[now + 1]);
	for (int i = 0; i < 5; i++)
		printf("%d", Data[i]);
	return 0;
}

 

Selection Sort

now = 0

 

0 ~ 5

now ~ howmany -1

howmany = len(Data)

 

now = 1

 

1 ~ 5

now ~ howmany - 1

min(Data[now:howmany])

where = Data.index(min(Data[now:howmany]))

Data[now], Data[where] = Data[where], Data[now]

 

now = 2

 

 

언제까지?

now == howmany - 1

 

Selection Sort

Data = [3, 2, 5, 4, 1, 6]
howmany = len(Data)

def solve(now):
    while now < howmany - 1:
        where = Data.index(min(Data[now:howmany]))
        Data[now], Data[where] = Data[where], Data[now]
        now += 1

solve(0)
print(Data)

 

Insertion Sort 1 단계

 

 

Insertion Sort 2 단계

 

 

int here = MyTurn - 1;

 

Insertion Sort 3 단계

 

int here = myTurn - 1;

if (Data[here] > key) Data[here + 1] = Data[here];

here--;

Data[here + 1] = key;

 

Insertion 4 단계

 

 

while((here >= 0) && (Data[here] > key))

 

public class InsertionSort {
    public static void main(String[] args) {
        int[] Data = {3, 2, 5, 4, 1};
        for (int myTurn = 1; myTurn < Data.length; myTurn++) {
            int key = Data[myTurn];
            int here = myTurn - 1;
            while ((here >= 0) && (Data[here] > key)) {
                Data[here + 1] = Data[here];
                here--;
            }
            Data[here + 1] = key;
        }

        for(int i = 0; i < Data.length; i++)
            System.out.println(Data[i]);
    }
}