Create 157-read-n-characters-given-read4.js

Author: everthis

157-read-n-characters-given-read4.js

@@ -0,0 +1,36 @@
+/**
+ * Definition for read4()
+ *
+ * @param {character[]} buf Destination buffer
+ * @return {number} The number of actual characters read
+ * read4 = function(buf) {
+ *     ...
+ * };
+ */
+
+/**
+ * @param {function} read4()
+ * @return {function}
+ */
+const solution = function(read4) {
+  const internalBuf = []
+  /**
+   * @param {character[]} buf Destination buffer
+   * @param {number} n Number of characters to read
+   * @return {number} The number of actual characters read
+   */
+  return function(buf, n) {
+    let readChars = 0
+    while (n > 0) {
+      if (internalBuf.length === 0) {
+        if (read4(internalBuf) === 0) {
+          return readChars
+        }
+      }
+      buf.push(internalBuf.shift())
+      readChars++
+      n--
+    }
+    return readChars
+  }
+}