[정렬] 선택 정렬

src/main/java/io/github/ones1kk/study/sorting/SelectionSort.java

@@ -0,0 +1,24 @@
+package io.github.ones1kk.study.sorting;
+
+public class SelectionSort {
+
+    public static void selectionSort(int[] arr, int size) {
+        for (int i = 0; i < size - 1; i++) {
+            int min_index = i;
+
+            for (int j = i + 1; j < size; j++) {
+                if (arr[j] < arr[min_index]) {
+                    min_index = j;
+                }
+            }
+
+            swap(arr, min_index, i);
+        }
+    }
+
+    private static void swap(int[] a, int i, int j) {
+        int temp = a[i];
+        a[i] = a[j];
+        a[j] = temp;
+    }
+}

src/test/groovy/io/github/ones1kk/study/sorting/SelectionSortTest.java

@@ -0,0 +1,32 @@
+package io.github.ones1kk.study.sorting;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+import java.util.Arrays;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class SelectionSortTest {
+
+    @ParameterizedTest
+    @ValueSource(strings = {
+            "3,7,5,2,1"
+            , "102,1,4,4214,123,3,6"
+    })
+    @DisplayName("선택 정렬")
+    void testSelectionSort(String value) {
+        // given
+        int[] arr = Arrays.stream(value.split(","))
+                .mapToInt(Integer::parseInt)
+                .toArray();
+
+        // when
+        SelectionSort.selectionSort(arr, arr.length);
+
+        // then
+        assertThat(arr).isSorted();
+    }
+
+}