結果
問題 | No.2127 Mod, Sum, Sum, Mod |
ユーザー |
👑 |
提出日時 | 2022-11-18 22:17:47 |
言語 | D (dmd 2.109.1) |
結果 |
AC
|
実行時間 | 27 ms / 2,000 ms |
コード長 | 4,748 bytes |
コンパイル時間 | 1,791 ms |
コンパイル使用メモリ | 155,732 KB |
実行使用メモリ | 6,948 KB |
最終ジャッジ日時 | 2024-06-22 16:44:15 |
合計ジャッジ時間 | 2,734 ms |
ジャッジサーバーID (参考情報) |
judge1 / judge4 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 27 |
ソースコード
import std.conv, std.functional, std.range, std.stdio, std.string;import std.algorithm, std.array, std.bigint, std.bitmanip, std.complex, std.container, std.math, std.mathspecial, 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)); }struct ModInt(uint M_) {import std.conv : to;alias M = M_;uint x;this(ModInt a) { x = a.x; }this(uint x_) { x = x_ % M; }this(ulong x_) { x = cast(uint)(x_ % M); }this(int x_) { x = ((x_ %= cast(int)(M)) < 0) ? (x_ + cast(int)(M)) : x_; }this(long x_) { x = cast(uint)(((x_ %= cast(long)(M)) < 0) ? (x_ + cast(long)(M)) : x_); }ref ModInt opAssign(T)(inout(T) a) if (is(T == uint) || is(T == ulong) || is(T == int) || is(T == long)) { return this = ModInt(a); }ref ModInt opOpAssign(string op, T)(T a) {static if (is(T == ModInt)) {static if (op == "+") { x = ((x += a.x) >= M) ? (x - M) : x; }else static if (op == "-") { x = ((x -= a.x) >= M) ? (x + M) : x; }else static if (op == "*") { x = cast(uint)((cast(ulong)(x) * a.x) % M); }else static if (op == "/") { this *= a.inv(); }else static assert(false);return this;} else static if (op == "^^") {if (a < 0) return this = inv()^^(-a);ModInt b = this, c = 1U;for (long e = a; e; e >>= 1) { if (e & 1) c *= b; b *= b; }return this = c;} else {return mixin("this " ~ op ~ "= ModInt(a)");}}ModInt inv() const {uint a = M, b = x; int y = 0, z = 1;for (; b; ) { const q = a / b; const c = a - q * b; a = b; b = c; const w = y - cast(int)(q) * z; y = z; z = w; }assert(a == 1); return ModInt(y);}ModInt opUnary(string op)() const {static if (op == "+") { return this; }else static if (op == "-") { ModInt a; a.x = x ? (M - x) : 0U; return a; }else static assert(false);}ModInt opBinary(string op, T)(T a) const { return mixin("ModInt(this) " ~ op ~ "= a"); }ModInt opBinaryRight(string op, T)(T a) const { return mixin("ModInt(a) " ~ op ~ "= this"); }bool opCast(T: bool)() const { return (x != 0U); }string toString() const { return x.to!string; }}enum MO = 998244353;alias Mint = ModInt!MO;// floor(n/x) = k// <=> k <= n/x < k+1// <=> n/(k+1) < x <= n/k// <=> floor(n/(k+1)) < x <= floor(n/k)void doFloors(alias fun, T)(const(T) n) {assert(n >= 1);for (T a = 0, b; a < n; a = b) {const k = n / (a + 1);b = n / k;// (a, b]: kfun(a, b, k);}}void main() {try {for (; ; ) {const N = readLong + 1;const M = readLong;Mint ans;doFloors!((long a, long b, long k) {chmax(a, 0);chmin(b, M);if (a < b) {debug {if (N <= 100) {writefln("(%s, %s]: %s", a, b, k);}}// Sum[Sum[r, {r, 0, j - 1}], {j, 1, m}]Mint calc0(long m) {return Mint(m - 1) * Mint(m) * Mint(m + 1) / 6;}// Sum[Sum[r, {r, 0, N - k j - 1}], {j, 1, m}]Mint calc1(long m) {const Mint N_ = N;const Mint k_ = k;const Mint m_ = m;return (3*k_*m_ + k_*k_*m_ + 3*k_*m_*m_ + 3*k_*k_*m_*m_ + 2*k_*k_*m_*m_*m_ - 6*m_*N_ - 6*k_*m_*N_ - 6*k_*m_*m_*N_ + 6*m_*N_*N_) / 12;}ans += Mint(k) * (calc0(b) - calc0(a));ans += (calc1(b) - calc1(a));}})(N);if (N < M) {ans += Mint(M - N) * Mint(N * (N - 1) / 2);}writeln(ans);debug {if (N <= 100 && M <= 100) {Mint brt;foreach (i; 1 .. N) foreach (j; 1 .. M + 1) {brt += i % j;}writeln("brt = ", brt);assert(brt == ans);}}}} catch (EOFException e) {}}