2024/9/29 多维dp 最后一题

src/main/java/com/cool/hot100/multi_dp/Num72.java

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+package com.cool.hot100.multi_dp;
+
+/**
+ * Created with IntelliJ IDEA.
+ *
+ * @Author: Cool
+ * @Date: 2024/09/30/1:53
+ * @Description: 72. 编辑距离
+ * Hard 2 看似mid实则hard
+ * Level 6
+ * DayNumber 3
+ * @Link https://leetcode.cn/problems/edit-distance/description/?envType=study-plan-v2&envId=top-100-liked
+ */
+public class Num72 {
+    public int minDistance(String word1, String word2) {
+        int nLen = word1.length();
+        int mLen = word2.length();
+        if (nLen * mLen == 0) {
+            return mLen + nLen;
+        }
+        int[][] dp = new int[nLen + 1][mLen + 1];
+        for (int i = 0; i < nLen + 1; i++) {
+            dp[i][0] = i;
+        }
+        for (int i = 0; i < mLen + 1; i++) {
+            dp[0][i] = i;
+        }
+        for (int i = 1; i < nLen + 1; i++) {
+            for (int j = 1; j < mLen + 1; j++) {
+                int leftToRight = dp[i - 1][j];
+                int rightToLeft = dp[i][j - 1];
+                int leftAndRight = dp[i - 1][j - 1];
+                if (word1.charAt(i - 1) == word2.charAt(j - 1)) {
+                    leftAndRight--;
+                }
+                dp[i][j] = Math.min(leftAndRight, Math.min(leftToRight, rightToLeft)) + 1;
+            }
+        }
+        return dp[nLen][mLen];
+    }
+}