feat: add Longest Chunked Palindrome Decomposition (#1184)

* add leetcode Longest Chunked Palindrome Decomposition

* Update leetcode/src/1147.c

Co-authored-by: David Leal <halfpacho@gmail.com>

* Update 1147.c

fix review

Co-authored-by: David Leal <halfpacho@gmail.com>

leetcode/DIRECTORY.md

@@ -108,6 +108,7 @@
 | 1009 | [Complement of Base 10 Integer](https://leetcode.com/problems/complement-of-base-10-integer/)                                   | [C](./src/1009.c) | Easy       |
 | 1026 | [Maximum Difference Between Node and Ancestor](https://leetcode.com/problems/maximum-difference-between-node-and-ancestor/description/)                          | [C](./src/1026.c) | Medium     |
 | 1089 | [Duplicate Zeros](https://leetcode.com/problems/duplicate-zeros/)                                                               | [C](./src/1089.c) | Easy       |
+| 1147 | [Longest Chunked Palindrome Decomposition](https://leetcode.com/problems/longest-chunked-palindrome-decomposition/description/) | [C](./src/1147.c) | Hard       |
 | 1184 | [Distance Between Bus Stops](https://leetcode.com/problems/distance-between-bus-stops/)                                         | [C](./src/1184.c) | Easy       |
 | 1189 | [Maximum Number of Balloons](https://leetcode.com/problems/maximum-number-of-balloons/)                                         | [C](./src/1189.c) | Easy       |
 | 1207 | [Unique Number of Occurrences](https://leetcode.com/problems/unique-number-of-occurrences/)                                     | [C](./src/1207.c) | Easy       |

leetcode/src/1147.c

@@ -0,0 +1,49 @@
+#define max(a,b) (((a)>(b))?(a):(b))
+
+bool equalSubstrings(char* text, int firstIndex, int secondIndex, int length){
+    for (int i = 0; i < length; i++){
+        if (text[firstIndex + i] != text[secondIndex + i]){
+            return false;
+        }
+    }
+
+    return true;
+}
+
+int longestDecompositionDpCached(char* text, int textLen, int index, int* dp){
+    if (2 * index >= textLen){
+        return 0;
+    }
+
+    if (dp[index] == 0){
+        dp[index] = longestDecompositionDp(text, textLen, index, dp);
+    }
+
+    return dp[index];
+}
+
+int longestDecompositionDp(char* text, int textLen, int index, int* dp){
+    char ch = text[index];
+    int result = 1;
+    
+    for (int i = 0; i < (textLen - 2 * index) / 2; i++){
+        if (ch == text[textLen - 1 - index - i] 
+            && equalSubstrings(text, index, textLen - 1 - index - i, i + 1)){
+                return max(result, 2 + longestDecompositionDpCached(text, textLen, index + i + 1, dp));
+        }
+    }
+
+    return result;
+}
+
+// Dynamic programming. Up -> down approach.
+// Runtime: O(n*n)
+// Space: O(n)
+int longestDecomposition(char * text){
+    int textLen = strlen(text);
+    int* dp = calloc(textLen, sizeof(int));
+    int result = longestDecompositionDpCached(text, textLen, 0, dp);
+
+    free(dp);
+    return result;
+}