add 583

fishercoder1534 · fishercoder1534 · commit 8956b5dfc67c · 2017-05-18T21:41:00.000-07:00
diff --git a/README.md b/README.md
@@ -20,6 +20,7 @@ Your ideas/fixes/algorithms are more than welcome!
 
 |  #  |      Title     |   Solutions   | Time          | Space         | Difficulty  | Tag          | Notes
 |-----|----------------|---------------|---------------|---------------|-------------|--------------|-----
+|583|[Delete Operation for Two Strings](https://leetcode.com/problems/delete-operation-for-two-strings/)|[Solution](../master/src/main/java/com/stevesun/solutions/_583.java) | O(m*n) |O(m*n) could be optimized to O(n) | Medium | DP
 |582|[Kill Process](https://leetcode.com/problems/kill-process/)|[Solution](../master/src/main/java/com/stevesun/solutions/_582.java) | O(n) |O(h) | Medium | Stack
 |581|[Shortest Unsorted Continuous Subarray](https://leetcode.com/problems/shortest-unsorted-continuous-subarray/)|[Solution](../master/src/main/java/com/stevesun/solutions/_581.java) | O(n) |O(1) | Easy | Array, Sort
 |575|[Distribute Candies](https://leetcode.com/problems/distribute-candies/)|[Solution](../master/src/main/java/com/stevesun/solutions/_575.java) | O(nlogn) |O(1) | Easy | Array
diff --git a/src/main/java/com/stevesun/solutions/_583.java b/src/main/java/com/stevesun/solutions/_583.java
@@ -0,0 +1,32 @@
+package com.stevesun.solutions;
+
+/**
+ * 583. Delete Operation for Two Strings
+ *
+ * Given two words word1 and word2, find the minimum number of steps required to make word1 and word2 the same, where in each step you can delete one character in either string.
+
+ Example 1:
+ Input: "sea", "eat"
+ Output: 2
+
+ Explanation: You need one step to make "sea" to "ea" and another step to make "eat" to "ea".
+
+ Note:
+ The length of given words won't exceed 500.
+ Characters in given words can only be lower-case letters.
+ */
+public class _583 {
+
+    public int minDistance(String word1, String word2) {
+        int m = word1.length();
+        int n = word2.length();
+        int[][] dp = new int[m+1][n+1];
+        for (int i = 1; i <= m; i++) {
+            for (int j = 1; j <= n; j++) {
+                dp[i][j] = word1.charAt(i-1) == word2.charAt(j-1) ? dp[i-1][j-1]+1 : Math.max(dp[i-1][j], dp[i][j-1]);
+            }
+        }
+        return m + n - 2*dp[m][n];
+    }
+
+}
diff --git a/src/test/java/com/stevesun/_583Test.java b/src/test/java/com/stevesun/_583Test.java
@@ -0,0 +1,36 @@
+package com.stevesun;
+
+import com.stevesun.solutions._48;
+import com.stevesun.solutions._583;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * Created by stevesun on 5/18/17.
+ */
+public class _583Test {
+    private static _583 test;
+    private static String word1;
+    private static String word2;
+
+    @BeforeClass
+    public static void setup(){
+        test = new _583();
+    }
+
+    @Test
+    public void test1(){
+        word1 = "sea";
+        word2 = "eat";
+        assertEquals(2, test.minDistance(word1, word2));
+    }
+
+    @Test
+    public void test2(){
+        word1 = "sea";
+        word2 = "ate";
+        assertEquals(4, test.minDistance(word1, word2));
+    }
+}
