add reorder log files

Author: beck chen

leetcode practice/array and strings/reorderLogFiles.js

@@ -0,0 +1,31 @@
+/**
+ * @param {string[]} logs
+ * @return {string[]}
+ */
+
+/* helper functions */
+const logComparator = (logA, logB) => {
+    // compare body first
+    const bodyCompareResult = getLogBody(logA).localeCompare(getLogBody(logB));
+    if (bodyCompareResult !== 0) { return bodyCompareResult; }
+
+    return logA.localeCompare(logB);
+}
+
+const getLogBody = logStr => logStr.slice(logStr.indexOf(' ') + 1, logStr.length);
+const getIsNumLog = logStr => /\d/.test(logStr);
+
+/* end of helper functions */
+
+var reorderLogFiles = function (logs) {
+    const digitLogs = [], letterLogs = [];
+    for (log of logs) {
+        if (getIsNumLog(getLogBody(log))) {
+            digitLogs.push(log);
+        } else {
+            letterLogs.push(log);
+        }
+    }
+
+    return [...letterLogs.sort(logComparator), ...digitLogs];
+};