feat: Problem016

src/main/java/com/doit/algorithm/kyoungsun/Problem016.java

@@ -0,0 +1,48 @@
+package com.doit.algorithm.kyoungsun;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Scanner;
+
+public class Problem016 {
+
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+        int N = scanner.nextInt();
+        int[] A = new int[N];
+        for (int i = 0; i < N; i++) {
+            A[i] = scanner.nextInt();
+        }
+        int solve = solve(N, A);
+        System.out.println(solve);
+    }
+
+    public static int solve(int n, int[] a) {
+        // 처음 인덱스 정보 저장
+        Map<Integer, Integer> beforeSort = new HashMap<>();
+        for (int i = 0; i < n; i++) {
+            beforeSort.put(a[i], i);
+        }
+
+        Arrays.sort(a);
+
+        Map<Integer, Integer> sorted = new HashMap<>();
+        for (int i = 0; i < n; i++) {
+            sorted.put(a[i], i);
+        }
+
+        int MAX = 0;
+        for (int i = 0; i < n; i++) {
+            int subtract = beforeSort.get(a[i]) - sorted.get(a[i]);
+            if (subtract > MAX) {
+                MAX = subtract;
+            }
+        }
+
+        return MAX + 1;
+    }
+
+}
+
+

src/test/java/com/doit/algorithm/kyoungsun/Problem016Test.java

@@ -0,0 +1,24 @@
+package com.doit.algorithm.kyoungsun;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class Problem016Test {
+
+    @Test
+    void testCase1() {
+        int N = 5;
+        int[] A = new int[]{10, 1, 5, 2, 3};
+        int solved = Problem016.solve(N, A);
+        assertThat(solved).isEqualTo(3);
+    }
+
+    @Test
+    void testCase2() {
+        int N = 5;
+        int[] A = new int[]{1, 3, 5, 7, 9};
+        int solved = Problem016.solve(N, A);
+        assertThat(solved).isEqualTo(1);
+    }
+}