tox.d

import std.stdio, std.algorithm, std.range, std.array, std.datetime.stopwatch;

struct Point { int x, y; }

auto f(int from_y, int to_y, int from_x, int to_x) {
    return chain( iota(from_y, to_y/2).map!(y => Point(from_x, y)),
                  iota(to_y/2, to_y)  .map!(y => Point(to_x, y)) ).array;   
}

auto g(int from_y, int to_y, int from_x, int to_x) {
    auto res = new Point[to_y - from_y];
    foreach(y; from_y .. to_y)
        res[y - from_y] = Point(y < to_y / 2 ? from_x : to_x, y); 
    return res;
}


void main() {
    auto sw = StopWatch(AutoStart.yes);
    auto r1 = f(20_000_000, 80_000_000, 1, 2);
    auto t1 = sw.peek();
    auto r2 = g(20_000_000, 80_000_000, 1, 2);
    auto t2 = sw.peek();
    writefln("f: %s, g: %s\t%s %s", t1, t2-t1, r1[$-1], r2[$-1]);
}