add 1745

Author: fishercoder1534

README.md

@@ -8,6 +8,7 @@ _If you like this project, please leave me a star._ ★
 
 |  #  |      Title     |   Solutions   | Video  | Difficulty  | Tag                   
 |-----|----------------|---------------|--------|-------------|-------------
+|1745|[Palindrome Partitioning IV](https://leetcode.com/problems/palindrome-partitioning-iv/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1745.java) ||Hard|String, DP|
 |1743|[Restore the Array From Adjacent Pairs](https://leetcode.com/problems/restore-the-array-from-adjacent-pairs/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1743.java) ||Medium|Greedy|
 |1742|[Maximum Number of Balls in a Box](https://leetcode.com/problems/maximum-number-of-balls-in-a-box/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1742.java) ||Easy|Array|
 |1736|[Latest Time by Replacing Hidden Digits](https://leetcode.com/problems/latest-time-by-replacing-hidden-digits/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1736.java) ||Easy|String, Greedy|

src/main/java/com/fishercoder/solutions/_1745.java

@@ -0,0 +1,36 @@
+package com.fishercoder.solutions;
+
+public class _1745 {
+    public static class Solution1 {
+        /**
+         * credit: https://leetcode.com/problems/palindrome-partitioning-iv/discuss/1042910/Java-Detailed-Explanation-DP-O(N2)
+         *
+         * check whether substring(i, j) is a palindrome becomes checking whether substring(i + 1, j -1) is a palindrome
+         *
+         * How we build the dp array:
+         *  start from the top right of this square matrix
+         */
+        public boolean checkPartitioning(String s) {
+            int n = s.length();
+            boolean[][] dp = new boolean[n][n];
+            for (int i = n - 1; i >= 0; i--) {
+                for (int j = i; j < n; j++) {
+                    if (s.charAt(i) == s.charAt(j)) {
+                        dp[i][j] = (i + 1 < j - 1) ? dp[i + 1][j - 1] : true;
+                    } else {
+                        dp[i][j] = false;
+                    }
+                }
+            }
+            for (int i = 1; i < n - 1; i++) {
+                for (int j = 1; j < n - 1; j++) {
+                    if (dp[0][i - 1] && dp[i][j] && dp[j + 1][n - 1]) {
+                        return true;
+                    }
+                }
+            }
+            return true;
+        }
+
+    }
+}

src/test/java/com/fishercoder/_1745Test.java

@@ -0,0 +1,36 @@
+package com.fishercoder;
+
+import com.fishercoder.solutions._1745;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class _1745Test {
+    private static _1745.Solution1 solution1;
+
+    @BeforeClass
+    public static void setup() {
+        solution1 = new _1745.Solution1();
+    }
+
+    @Test
+    public void test1() {
+        assertEquals(true, solution1.checkPartitioning("abcbdd"));
+    }
+
+    @Test
+    public void test2() {
+        assertEquals(false, solution1.checkPartitioning("bcbddxy"));
+    }
+
+    @Test
+    public void test3() {
+        assertEquals(true, solution1.checkPartitioning("juchzcedhfesefhdeczhcujzzvbmoeombv"));
+    }
+
+    @Test
+    public void test4() {
+        assertEquals(true, solution1.checkPartitioning("gbofdldvwelqiizbievfolrujxnwjmjwsjrjeqecwssgtlteltslfzkblzihcgwjnqaiqbxohcnxulxozzkanaofgoddogfoanakzzoxluxnchoxbqiaqnjwgchizlbkzflstletltgsswceqejrjswjmjwnxjurlofveibziiqlewvdldfobgxebrcrbexv"));
+    }
+}