2024/9/25 Hot100 dp

src/main/java/com/cool/hot100/dp/Num139.java

@@ -0,0 +1,44 @@
+package com.cool.hot100.dp;
+
+import org.junit.Test;
+
+import java.util.*;
+
+/**
+ * Created with IntelliJ IDEA.
+ *
+ * @Author: Cool
+ * @Date: 2024/09/24/16:11
+ * DayNumber 2
+ * Hard 2
+ * Level ?
+ * @Description 139. 单词拆分
+ * @Link https://leetcode.cn/problems/word-break/description/?envType=study-plan-v2&envId=top-100-liked
+ */
+public class Num139 {
+    public boolean wordBreak(String s, List<String> wordDict) {
+        Set<String> wordDictSet = new HashSet(wordDict);
+        boolean[] dp = new boolean[s.length() + 1];
+        Arrays.fill(dp, false);
+        dp[0] = true;
+        // dp[i]表示从0-i的字符串，是否可以用wordDict来表示
+        for(int i=1;i<s.length()+1;i++){
+            for(int j=0;j<i;j++){
+                if(dp[j]&&wordDictSet.contains(s.substring(j,i))){
+                    dp[i]=true;
+                    break;
+                }
+            }
+        }
+        return dp[s.length()];
+    }
+
+    @Test
+    public void test(){
+        List<String> list=new ArrayList<>();
+        list.add("leet");
+        list.add("code");
+
+        wordBreak("leetcode",list);
+    }
+}

src/main/java/com/cool/hot100/dp/Num300.java

@@ -0,0 +1,15 @@
+package com.cool.hot100.dp;
+
+/**
+ * Created with IntelliJ IDEA.
+ *
+ * @Author: Cool
+ * @Date: 2024/09/24/16:45
+ * DayNumber 3
+ * Hard 2
+ * Level ?
+ * @Description 300. 最长递增子序列
+ * @Link https://leetcode.cn/problems/longest-increasing-subsequence/description/?envType=study-plan-v2&envId=top-100-liked
+ */
+public class Num300 {
+}

src/main/java/com/cool/hot100/dp/Num322.java

@@ -0,0 +1,28 @@
+package com.cool.hot100.dp;
+
+import java.util.Arrays;
+
+/**
+ * Created with IntelliJ IDEA.
+ *
+ * @Author: Cool
+ * @Date: 2024/09/24/15:31
+ * DayNumber 1
+ * Hard 2
+ * Level ?
+ * @Description 322. 零钱兑换
+ * @Link https://leetcode.cn/problems/coin-change/description/?envType=study-plan-v2&envId=top-100-liked
+ */
+public class Num322 {
+    public int coinChange(int[] coins, int amount) {
+        int[] dp = new int[amount + 1];
+        Arrays.fill(dp, amount + 1);
+        dp[0] = 0;
+        for (int i = 0; i < coins.length; i++) {
+            for (int j = coins[i]; j <= amount; j++) {
+                dp[j] = Math.min(dp[j], dp[j - coins[i]] + 1);
+            }
+        }
+        return dp[amount] == amount + 1 ? -1 : dp[amount];
+    }
+}