add PROGRAMMERS-12913

Author: codejsha

README.md

@@ -7,6 +7,7 @@
 | PROGRAMMERS-1844          | [python](programmers/problem1844)  | [게임 맵 최단거리 (The Shortest Distance on Game Map)](https://school.programmers.co.kr/learn/courses/30/lessons/1844)                |
 | PROGRAMMERS-12909 :star:  | [java](programmers/problem12909)   | [올바른 괄호 (A Correct Parentheses)](https://school.programmers.co.kr/learn/courses/30/lessons/12909)                                |
 | PROGRAMMERS-12911         | [java](programmers/problem12911)   | [다음 큰 숫자 (Next Big Number)](https://school.programmers.co.kr/learn/courses/30/lessons/12911)                                     |
+| PROGRAMMERS-12913         | [java](programmers/problem12913)   | [땅따먹기 (Hopscotch)](https://school.programmers.co.kr/learn/courses/30/lessons/12913)                                               |
 | PROGRAMMERS-12914         | [java](programmers/problem12914)   | [멀리 뛰기 (Long Jump)](https://school.programmers.co.kr/learn/courses/30/lessons/12914)                                              |
 | PROGRAMMERS-12924 :star:  | [java](programmers/problem12924)   | [숫자의 표현 (Number Expressions)](https://school.programmers.co.kr/learn/courses/30/lessons/12924)                                   |
 | PROGRAMMERS-12927         | [java](programmers/problem12927)   | [야근 지수 (Overtime Index)](https://school.programmers.co.kr/learn/courses/30/lessons/12927)                                         |

programmers/problem12913/Hopscotch_DFS.java

@@ -0,0 +1,36 @@
+package problem12913;
+
+/**
+ * DFS solution
+ * this solution is not accepted because of time limit exceeded
+ */
+public class Hopscotch_DFS {
+    public static void main(String[] args) {
+        final var sol = new Hopscotch_DFS();
+        final var land = new int[][]{{1, 2, 3, 5}, {5, 6, 7, 8}, {4, 3, 2, 1}};
+        final var expected = 16;
+        final var result = sol.solution(land);
+        System.out.println("expected: " + expected + " result: " + result);
+    }
+
+    public int solution(int[][] land) {
+        var max = 0;
+        for (var i = 0; i < land[0].length; i++) {
+            max = Math.max(max, dfs(land, 0, i, 0));
+        }
+        return max;
+    }
+
+    private int dfs(int[][] land, int row, int col, int sum) {
+        if (row == land.length) {
+            return sum;
+        }
+        var max = 0;
+        for (var i = 0; i < land[row].length; i++) {
+            if (i != col) {
+                max = Math.max(max, dfs(land, row + 1, i, sum + land[row][i]));
+            }
+        }
+        return max;
+    }
+}

programmers/problem12913/Hopscotch_DP.java

@@ -0,0 +1,39 @@
+package problem12913;
+
+import java.util.Arrays;
+
+/**
+ * DP solution
+ */
+public class Hopscotch_DP {
+    public static void main(String[] args) {
+        final var sol = new Hopscotch_DP();
+        final var land = new int[][]{{1, 2, 3, 5}, {5, 6, 7, 8}, {4, 3, 2, 1}};
+        final var expected = 16;
+        final var result = sol.solution(land);
+        System.out.println("expected: " + expected + " result: " + result);
+    }
+
+    public int solution(int[][] land) {
+        final var dp = new int[land.length][land[0].length];
+        // copy first row
+        System.arraycopy(land[0], 0, dp[0], 0, land[0].length);
+
+        // i = row, j and k = col
+        for (var i = 1; i < land.length; i++) {
+            for (var j = 0; j < land[i].length; j++) {
+                for (var k = 0; k < land[i].length; k++) {
+                    if (j != k) {
+                        dp[i][j] = Math.max(dp[i][j], dp[i - 1][k] + land[i][j]);
+                    }
+                }
+            }
+        }
+
+        var max = 0;
+        for (var i = 0; i < land[0].length; i++) {
+            max = Math.max(max, dp[land.length - 1][i]);
+        }
+        return max;
+    }
+}