2022-08-20 update: added "Minimum Number of Refueling Stops" (#72)

Author: fartem

README.md

@@ -33,6 +33,7 @@ Soon.
 | 239. Sliding Window Maximum                   | [Link](https://leetcode.com/problems/sliding-window-maximum/)                    | [Link](./src/main/java/com/smlnskgmail/jaman/leetcodejava/hard/SlidingWindowMaximum.java)                 |
 | 297. Serialize and Deserialize Binary Tree    | [Link](https://leetcode.com/problems/serialize-and-deserialize-binary-tree/)     | [Link](./src/main/java/com/smlnskgmail/jaman/leetcodejava/hard/SerializeAndDeserializeBinaryTree.java)    |
 | 458. Poor Pigs                                | [Link](https://leetcode.com/problems/poor-pigs/)                                 | [Link](./src/main/java/com/smlnskgmail/jaman/leetcodejava/hard/PoorPigs.java)                             |
+| 871. Minimum Number of Refueling Stops        | [Link](https://leetcode.com/problems/minimum-number-of-refueling-stops/)         | [Link](./src/main/java/com/smlnskgmail/jaman/leetcodejava/hard/MinimumNumberOfRefuelingStops.java)        |
 | 1106. Parsing A Boolean Expression            | [Link](https://leetcode.com/problems/parsing-a-boolean-expression/)              | [Link](./src/main/java/com/smlnskgmail/jaman/leetcodejava/hard/ParsingABooleanExpression.java)            |
 | 1220. Count Vowels Permutation                | [Link](https://leetcode.com/problems/count-vowels-permutation/)                  | [Link](./src/main/java/com/smlnskgmail/jaman/leetcodejava/hard/CountVowelsPermutation.java)               |
 | 1944. Number of Visible People in a Queue     | [Link](https://leetcode.com/problems/number-of-visible-people-in-a-queue/)       | [Link](./src/main/java/com/smlnskgmail/jaman/leetcodejava/hard/NumberOfVisiblePeopleInAQueue.java)        |

src/main/java/com/smlnskgmail/jaman/leetcodejava/hard/MinimumNumberOfRefuelingStops.java

@@ -0,0 +1,35 @@
+package com.smlnskgmail.jaman.leetcodejava.hard;
+
+// https://leetcode.com/problems/minimum-number-of-refueling-stops/
+public class MinimumNumberOfRefuelingStops {
+
+    private final int target;
+    private final int startFuel;
+    private final int[][] stations;
+
+    public MinimumNumberOfRefuelingStops(int target, int startFuel, int[][] stations) {
+        this.target = target;
+        this.startFuel = startFuel;
+        this.stations = stations;
+    }
+
+    public int solution() {
+        int n = stations.length;
+        long[] dp = new long[n + 1];
+        dp[0] = startFuel;
+        for (int i = 0; i < n; i++) {
+            for (int j = i; j >= 0; j--) {
+                if (dp[j] >= stations[i][0]) {
+                    dp[j + 1] = Math.max(dp[j + 1], dp[j] + (long) stations[i][1]);
+                }
+            }
+        }
+        for (int i = 0; i <= n; i++) {
+            if (dp[i] >= target) {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+}

src/test/java/com/smlnskgmail/jaman/leetcodejava/hard/MinimumNumberOfRefuelingStopsTest.java

@@ -0,0 +1,17 @@
+package com.smlnskgmail.jaman.leetcodejava.hard;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class MinimumNumberOfRefuelingStopsTest {
+
+    @Test
+    public void defaultTest() {
+        assertEquals(
+                0,
+                new MinimumNumberOfRefuelingStops(1, 1, new int[][]{}).solution()
+        );
+    }
+
+}