https://leetcode.com/problems/jump-game/

interview_prep/algorithm/java/src/main/java/hoa/can/code/ez/PartitionEqualSubSetSum.java

@@ -1,7 +1,5 @@
 package hoa.can.code.ez;
 
-import java.util.Arrays;
-
 import util.Array;
 
 public class PartitionEqualSubSetSum {
@@ -12,7 +10,6 @@ public static int equalPartition(int n, int arr[]){
     }
 
     static int canAddUp(int arr[], int target){
-        System.out.println(String.format("canAddUp %d %s", target, Arrays.toString(arr)));
         if(target==0){
             return 1;
         }

interview_prep/algorithm/java/src/main/java/hoa/can/code/gg/Jumping.java

@@ -3,16 +3,24 @@
 import java.util.Arrays;
 
 /**
- * https://leetcode.com/problems/jump-game/
+ * <a href="https://leetcode.com/problems/jump-game/">Desc</a>
  */
 public class Jumping {
-    final static int NO_WAY = Integer.MAX_VALUE;
+    final static int NO_WAY = 10000;
+
     public static boolean canJump(int[] nums) {
+        int step = minJumps(nums);
+        return (step != NO_WAY);
+    }
+
+    public static int minJumps(int[] nums) {
         int[] memo = new int[nums.length];
         Arrays.fill(memo, -1);
-        return (minJumps(nums, 0, nums.length - 1, memo) > -1);
+        int lastIdx = nums.length - 1;
+        return minJumps(nums, 0, lastIdx, memo);
     }
-    private static int minJumps(int steps[], int begin, int dest, int[] memo) {
+
+    private static int minJumps(int[] steps, int begin, int dest, int[] memo) {
         if (begin == dest)
             return 0;
         if (steps[begin] == 0)

interview_prep/algorithm/java/src/main/java/hoa/can/code/gg/JumpingQuickly.java

@@ -0,0 +1,24 @@
+package hoa.can.code.gg;
+
+public class JumpingQuickly {
+    public static int minJumps(int[] nums) {
+        int n = nums.length;
+        if (n <= 1) {
+            return 0;
+        }
+
+        int maxReach = nums[0];
+        int steps = 1;
+        int currentMax = nums[0];
+
+        for (int i = 1; i < n; i++) {
+            if (i > maxReach) {
+                steps++;
+                maxReach = currentMax;
+            }
+
+            currentMax = Math.max(currentMax, i + nums[i]);
+        }
+        return steps;
+    }
+}

interview_prep/algorithm/java/src/test/java/hoa/can/code/JumpingTest.java

@@ -1,23 +1,71 @@
 package hoa.can.code;
 
+import hoa.can.code.gg.JumpingQuickly;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 
 import static hoa.can.code.gg.Jumping.canJump;
+import static hoa.can.code.gg.Jumping.minJumps;
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 public class JumpingTest {
     @Test
     @DisplayName("ok")
     public void yes() {
-        assertEquals(true, canJump(new int[]{2, 3, 1, 1, 4}));
-        assertEquals(true, canJump(new int[]{1, 3, 5, 8, 9, 2, 6, 7, 6, 8, 9}));
+        assertTrue(canJump(new int[]{0}));
+        assertTrue(canJump(new int[]{2, 3, 1, 1, 4}));
+        assertTrue(canJump(new int[]{1, 3, 5, 8, 9, 2, 6, 7, 6, 8, 9}));
+        assertTrue(canJump(new int[]{3, 2, 1, 1, 1, 2, 3, 4, 5, 1, 3, 0, 2, 3, 0, 3, 1, 2, 3, 9, 1, 0, 0, 4, 1, 1, 1, 0, 2, 3, 4, 0, 9, 0, 0, 1, 2, 3, 9, 0, 0, 1, 0, 0, 1, 0, 1, 2, 3, 4}));
     }
 
     @Test
     @DisplayName("nope")
     public void no() {
-        assertEquals(true, canJump(new int[]{0}));
-        assertEquals(true, canJump(new int[]{0,1}));
+        assertFalse(canJump(new int[]{0, 1}));
+        assertFalse(canJump(new int[]{3, 2, 1, 0, 4}));
+        assertFalse(canJump(new int[]{2, 0, 0, 0, 3}));
+        assertFalse(canJump(new int[]{4, 3, 2, 1, 0, 0, 0}));
+        assertFalse(canJump(new int[]{3, 2, 1, 0, 1, 2, 3, 4, 5, 1, 0, 0, 2, 3, 0, 0, 1, 2, 3, 0, 1, 0, 0, 4, 1, 1, 1, 0, 2, 3, 4, 0, 0, 0, 0, 1, 2, 3, 4, 0, 0, 1, 0, 0, 1, 0, 1, 2, 3, 4}));
+    }
+
+    @Test
+    @DisplayName("yes-WithDetail")
+    public void yesWithDetail() {
+        assertEquals(
+                2,
+                minJumps(new int[]{10,8,12,17,1,21,5,17,20,11,5,27,23,8,12,18,16,12,9,8,17,12,23,26,0,5,9,24,10}),
+                "10 -> 20 -> end"
+        );
+
+        assertEquals(
+                2,
+                minJumps(new int[]{2,3,1,1,4}),
+                "2 -> 3 -> end"
+        );
+
+        assertEquals(
+                3,
+                minJumps(new int[]{2,3,1,1,1,4}),
+                "2 -> 3 -> end"
+        );
+
+        assertEquals(
+                5,
+                minJumps(new int[]{1,1,1,1,1,1}),
+                "2 -> 3 -> end"
+        );
+
+    }
+
+    @Test
+    @DisplayName("nope")
+    public void nope() {
+        assertEquals(
+                13,
+                JumpingQuickly.minJumps(new int[]{8,2,4,4,4,9,5,2,5,8,8,0,8,6,9,1,1,6,3,5,1,2,6,6,0,4,8,6,0,3,2,8,7,6,5,1,7,0,3,4,8,3,5,9,0,4,0,1,0,5,9,2,0,7,0,2,1,0,8,2,5,1,2,3,9,7,4,7,0,0,1,8,5,6,7,5,1,9,9,3,5,0,7,5}),
+                "quick"
+        );
     }
 }

interview_prep/algorithm/java/src/test/java/hoa/can/PartitionEqualSubSetSumTest.java → interview_prep/algorithm/java/src/test/java/hoa/can/code/PartitionEqualSubSetSumTest.java

@@ -1,4 +1,4 @@
-package hoa.can;
+package hoa.can.code;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;