import std.conv, std.functional, std.range, std.stdio, std.string; import std.algorithm, std.array, std.bigint, std.complex, std.container, std.math, std.numeric, std.regex, std.typecons; import core.bitop; class EOFException : Throwable { this() { super("EOF"); } } string[] tokens; string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; } int readInt() { return readToken.to!int; } long readLong() { return readToken.to!long; } real readReal() { return readToken.to!real; } bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } } bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } } int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; } int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); } int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); } int N, A, B; real[] X, Y; int calc(real d) { int cnt; foreach (i; 0 .. N) foreach (j; i + 1 .. N) { if ((X[i] - X[j])^^2 + (Y[i] - Y[j])^^2 <= d^^2) { ++cnt; } } return cnt; } void doIt(int l, int x, int y, int r, int s0, int s1, int dir) { debug { writefln("N = %d, A = %d, B = %d; B' = %d", N, A, B, N * (N - 1) / 2 - B); writefln(" l = %d, x = %d, y = %d, r = %d; s0 = %d, s1 = %d, dir = %d", l, x, y, r, s0, s1, dir); } /* |--------20----| |----20--------| l x 1 y */ enum real C = 1e-4; enum real D = 1e-4 * tan(1.0); enum real E = 1e-4 * tan(2.0); debug { writefln(" C = %.10f", C); writefln(" D = %.10f", D); writefln(" E = %.10f", E); } X = new real[N]; Y = new real[N]; foreach (i; 0 .. l) { X[i] = C * i; Y[i] = 0.0; } foreach (j; 0 .. x) { X[l + j] = 18.0 + D * j; Y[l + j] = 0.0; } X[l + x] = 20.0 + C * (r - 0.5); Y[l + x] = 0.0; foreach (j; 0 .. y) { X[l + x + 1 + j] = 25.0 + E * j; Y[l + x + 1 + j] = 0.0; } debug { writeln(" X = ", X); writeln(" Y = ", Y); writeln(" 10: ", calc(10.0)); writeln(" 20: ", calc(20.0)); } assert(calc(10.0) == s0); assert(calc(20.0) == B); int now = s0; foreach (j; 0 .. x) { real t0 = 18.0 + D * j; real t1 = 8.0 + D * j; Tuple!(real, int)[] events; events ~= tuple(t0, 0); events ~= tuple(t1, 0); foreach (i; 0 .. l + j) { real t = X[i] + 10.0; if (t1 <= t && t <= t0) { events ~= tuple(t, +1); } } foreach (i; l + j + 1 .. N) { real t = X[i] - 10.0; if (t1 <= t && t <= t0) { events ~= tuple(t, -1); } } sort(events); debug { writeln(" events = ", events); } const eventsLen = cast(int)(events.length); int best = now, cur; int hm; cur = now; foreach_reverse (h; 1 .. eventsLen) { cur += events[h][1]; if ((dir == 0) ? chmax(best, cur) : chmin(best, cur)) { hm = h; } } bool ok; cur = now; foreach_reverse (h; 1 .. eventsLen) { cur += events[h][1]; if (cur == A) { ok = true; X[l + j] = (events[h][0] + events[h - 1][0]) / 2.0; debug { writeln(" j = ", j); writeln(" ", cur, " ", calc(10.0)); } break; } } if (ok) { break; } X[l + j] = (events[hm][0] + events[hm - 1][0]) / 2.0; now = best; debug { writeln(" j = ", j); writeln(" X = ", X); writeln(" ", now, " ", calc(10.0)); } } assert(calc(10.0) == A); assert(calc(20.0) == B); } void main() { debug { foreach (n; 1 .. 50) { foreach (b; (n * (n - 1) + 3) / 4 + n .. n * (n - 1) / 2 + 1) { // writefln("n = %d, b = %d", n, b); auto flg = new bool[n * (n - 1) / 2 + 1]; foreach (l; 0 .. n + 1) { foreach (x; 0 .. (n - l - 1) + 1) { const y = n - l - 1 - x; foreach (r; 0 .. l + 1) { if (n * (n - 1) / 2 - b == 0 * x + r + l * y) { const scores = [ l * (l - 1) / 2 + (n - l) * (n - l - 1) / 2, (l + x) * (l + x - 1) / 2 + (n - l - x) * (n - l - x - 1) / 2 ]; foreach (score; min(scores[0], scores[1]) .. max(scores[0], scores[1]) + 1) { flg[score] = true; } } } } } // writefln(" [%d, %d]", mn, mx); foreach (a; (n * (n - 1) + 3) / 4 .. b - n + 1) { assert(flg[a]); } } } } try { for (; ; ) { N = readInt(); A = readInt(); B = readInt(); foreach (l; 0 .. N + 1) { foreach (x; 0 .. (N - l - 1) + 1) { const y = N - l - 1 - x; int r = N * (N - 1) / 2 - B; if (y > 0) { r %= y; } if (0 <= r && r <= l && N * (N - 1) / 2 - B == 0 * x + r + l * y) { int s0 = l * (l - 1) / 2 + (N - l) * (N - l - 1) / 2; int s1 = (l + x) * (l + x - 1) / 2 + (N - l - x) * (N - l - x - 1) / 2; if (s0 <= A && A <= s1) { doIt(l, x, y, r, s0, s1, 0); goto done; } if (s1 <= A && A <= s0) { doIt(l, x, y, r, s0, s1, 1); goto done; } } } } assert(false); done: foreach (i; 0 .. N) { writefln("%.10f %.10f", X[i], Y[i]); } } } catch (EOFException e) { } }