refactor 474

fishercoder1534 · fishercoder1534 · commit 75065518a3bd · 2021-04-02T08:07:59.000-07:00
diff --git a/src/main/java/com/fishercoder/solutions/_474.java b/src/main/java/com/fishercoder/solutions/_474.java
@@ -2,6 +2,19 @@
 
 public class _474 {
     public static class Solution1 {
+        /**
+         * credit: https://leetcode.com/problems/ones-and-zeroes/discuss/95811/Java-Iterative-DP-Solution-O(mn)-Space and
+         * https://leetcode.com/problems/ones-and-zeroes/discuss/95811/Java-Iterative-DP-Solution-O(mn)-Space/100352
+         * <p>
+         * The problem can be interpreted as:
+         * What's the max number of str can we pick from strs with limitation of m "0"s and n "1"s.
+         *
+         * Thus we can define dp[i][j] as it stands for max number of str can we pick from strs with limitation of i "0"s and j "1"s.
+         *
+         * For each str, assume it has a "0"s and b "1"s, we update the dp array iteratively
+         * and set dp[i][j] = Math.max(dp[i][j], dp[i - a][j - b] + 1).
+         * So at the end, dp[m][n] is the answer.
+         */
         public int findMaxForm(String[] strs, int m, int n) {
             int[][] dp = new int[m + 1][n + 1];
             for (String str : strs) {
