Create 474-ones-and-zeroes.js

Author: everthis

474-ones-and-zeroes.js

@@ -0,0 +1,36 @@
+/**
+ * @param {string[]} strs
+ * @param {number} m
+ * @param {number} n
+ * @return {number}
+ */
+
+const findMaxForm = function(strs, m, n) {
+    const memo = Array.from(new Array(m+1), () => new Array(n+1).fill(0) )
+    let numZeroes;
+    let numOnes;
+    
+    for (let s of strs) {
+      numZeroes = numOnes = 0;
+      // count number of zeroes and ones in current string
+      for (let c of s) {
+        if (c == '0')
+      numZeroes++;
+        else if (c == '1')
+      numOnes++;
+      }
+  
+      // memo[i][j] = the max number of strings that can be formed with i 0's and j 1's
+      // from the first few strings up to the current string s
+      // Catch: have to go from bottom right to top left
+      // Why? If a cell in the memo is updated(because s is selected),
+      // we should be adding 1 to memo[i][j] from the previous iteration (when we were not considering s)
+      // If we go from top left to bottom right, we would be using results from this iteration => overcounting
+      for (let i = m; i >= numZeroes; i--) {
+        for (let j = n; j >= numOnes; j--) {
+          memo[i][j] = Math.max(memo[i][j], memo[i - numZeroes][j - numOnes] + 1);
+        }
+      }
+    }
+    return memo[m][n];
+  }