From 42bbdd309b44582779537648d4a72b328018b82b Mon Sep 17 00:00:00 2001
From: fanxb <fleyx20@outlook.com>
Date: Thu, 10 Mar 2022 15:09:47 +0800
Subject: [PATCH] add

---
 5.leetcode/src/com/fanxb/common/Q131.java | 66 +++++++++++++++++++++++
 5.leetcode/src/com/fanxb/common/Q132.java | 51 ++++++++++++++++++
 2 files changed, 117 insertions(+)
 create mode 100644 5.leetcode/src/com/fanxb/common/Q131.java
 create mode 100644 5.leetcode/src/com/fanxb/common/Q132.java

diff --git a/5.leetcode/src/com/fanxb/common/Q131.java b/5.leetcode/src/com/fanxb/common/Q131.java
new file mode 100644
index 0000000..4b018d7
--- /dev/null
+++ b/5.leetcode/src/com/fanxb/common/Q131.java
@@ -0,0 +1,66 @@
+package com.fanxb.common;
+
+import java.util.*;
+
+/**
+ * 分割回文串
+ *
+ * @author fanxb
+ * @date 2022/3/9 10:10
+ */
+public class Q131 {
+
+    public List<List<String>> partition(String s) {
+        //先用dp找到所有符合条件的回文
+        boolean[][] dp = new boolean[s.length()][s.length()];
+        for (int j = 0; j < dp.length; j++) {
+            for (int i = 0; i <= j; i++) {
+                if (i == j) {
+                    dp[i][j] = true;
+                } else {
+                    boolean b = s.charAt(i) == s.charAt(j);
+                    if (i + 1 == j) {
+                        dp[i][j] = b;
+                    } else {
+                        dp[i][j] = dp[i + 1][j - 1] && b;
+                    }
+                }
+            }
+        }
+        List<List<String>> res = new ArrayList<>();
+        dfs(s, 0, new Stack<>(), res, dp);
+        return res;
+
+    }
+
+    /**
+     * 分割字符串
+     *
+     * @param s     字符串
+     * @param index 子串的起始位置
+     * @param temp  临时存储已经分割后的字符串
+     * @param res   存储最终分割结果
+     * @param dp    dp结果
+     * @author fanxb
+     * date 2022/3/9 16:39
+     */
+    private void dfs(String s, int index, Stack<String> temp, List<List<String>> res, boolean[][] dp) {
+        if (index == s.length()) {
+            res.add(new ArrayList<>(temp));
+            return;
+        }
+        for (int i = index; i < s.length(); i++) {
+            if (dp[index][i + 1]) {
+                String tempS = s.substring(index, i + 1);
+                temp.push(tempS);
+                dfs(s, i + 1, temp, res, dp);
+                temp.pop();
+            }
+
+        }
+    }
+
+
+    public static void main(String[] args) {
+    }
+}
diff --git a/5.leetcode/src/com/fanxb/common/Q132.java b/5.leetcode/src/com/fanxb/common/Q132.java
new file mode 100644
index 0000000..f3ae28f
--- /dev/null
+++ b/5.leetcode/src/com/fanxb/common/Q132.java
@@ -0,0 +1,51 @@
+package com.fanxb.common;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Stack;
+
+/**
+ * 分割回文串
+ *
+ * @author fanxb
+ * @date 2022/3/9 10:10
+ */
+public class Q132 {
+
+    public int minCut(String s) {
+        //先用dp找到所有符合条件的回文
+        boolean[][] dp = new boolean[s.length()][s.length()];
+        for (int j = 0; j < dp.length; j++) {
+            for (int i = 0; i <= j; i++) {
+                if (i == j) {
+                    dp[i][j] = true;
+                } else {
+                    boolean b = s.charAt(i) == s.charAt(j);
+                    if (i + 1 == j) {
+                        dp[i][j] = b;
+                    } else {
+                        dp[i][j] = dp[i + 1][j - 1] && b;
+                    }
+                }
+            }
+        }
+        //再次dp找到最小分割次数.定义minArr[i]为从0到i的最小分割次数
+        int[] minArr = new int[s.length()];
+        for (int i = 1; i < s.length(); i++) {
+            //定义l，当l->i构成回文串时，此时分割次数为=minArr[l-1]+1.找到最小的l
+            int temp = i;
+            for (int l = 0; l <= i; l++) {
+                if (dp[l][i]) {
+                    temp = Math.min(temp, l == 0 ? 0 : minArr[l - 1] + 1);
+                }
+            }
+            minArr[i] = temp;
+        }
+        return minArr[s.length() - 1];
+    }
+
+
+    public static void main(String[] args) {
+        System.out.println(new Q132().minCut("aab"));
+    }
+}