Update 1531-string-compression-ii.js

Author: everthis

1531-string-compression-ii.js

@@ -24,3 +24,38 @@ const getLengthOfOptimalCompression = function(s, k) {
   }
   return counter(0, '', 0, k)
 };
+
+// another
+
+const getLengthOfOptimalCompression = function (s, k) {
+  const n = s.length
+  const dp = new Array(n + 1).fill(n).map((row) => new Array(k + 1).fill(n))
+  dp[0][0] = 0
+
+  for (let i = 1; i <= n; i++) {
+    for (let j = 0; j <= k; j++) {
+      let letterCount = 0
+      let deletion = 0
+      // keep s[i], compress same letters, remove different letters
+      for (let l = i; l >= 1; l--) {
+        if (s.charAt(l - 1) === s.charAt(i - 1)) letterCount++
+        else deletion++
+        // places = length needed to rep compressed letters.
+        // 0 places for count = 1,0, 1 place = <10, 10-99 requires 2 places, 100+ requires 3
+        let places = 0
+        if (letterCount >= 100) places = 3
+        else if (letterCount >= 10) places = 2
+        else if (letterCount >= 2) places = 1
+        if (j - deletion >= 0) {
+          dp[i][j] = Math.min(dp[i][j], dp[l - 1][j - deletion] + 1 + places)
+        }
+      }
+      // delete
+      if (j > 0) {
+        dp[i][j] = Math.min(dp[i][j], dp[i - 1][j - 1])
+      }
+    }
+  }
+  return dp[n][k]
+}
+