Data commit

Task/Longest-string-challenge/D/longest-string-challenge.d

@@ -0,0 +1,19 @@
+import std.stdio, std.array;
+
+/// Return a.length - b.length if positive, 0 otherwise.
+int longer(string a, string b) {
+    while (!a.empty && !b.empty)
+        a.popFront(), b.popFront();
+    return a.length;
+}
+
+void main() {
+    string longest, lines;
+    foreach (string line; stdin.lines())
+        if (longer(line, longest))
+            lines = longest = line;
+        else if (!longer(longest, line))
+            lines ~= line;
+
+    writeln(lines);
+}