Submission #3324797

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Source Code Expand

void main() {
  import std.stdio, std.string, std.conv, std.algorithm;

  long a;
  int k;
  rd(a, k);
  long _a = a;
  int[] n;
  while (_a) {
    n = (_a % 10) ~ n;
    _a /= 10;
  }

  long maa() { // a以下の最大の整数
    import core.bitop : popcnt;

    auto dp = new long[][][][](n.length + 1, 2, 2, 1 << 10);
    foreach (i; 0 .. (n.length + 1)) {
      foreach (bit; 0 .. (1 << 10)) {
        dp[i][0][0][bit] = -1;
        dp[i][0][1][bit] = -1;
        dp[i][1][0][bit] = -1;
        dp[i][1][1][bit] = -1;
      }
    }
    dp[0][0][0][0] = 0; // ?
    void chmax(ref long l, long r) {
      l = max(l, r);
    }

    foreach (i; 0 .. n.length) {
      foreach (l; 0 .. 2) {
        foreach (z; 0 .. 2) {
          foreach (b; 0 .. (1 << 10)) {
            if (dp[i][l][z][b] >= 0) {
              auto d = l ? 9 : n[i];
              for (int digit = 0; digit <= d; digit++) {
                auto less = l || (digit < d);
                auto zero = z || (digit > 0);
                auto bit = !zero ? b : (b | (1 << digit));
                chmax(dp[i + 1][less][zero][bit], dp[i][l][z][b] * 10 + digit);
              }
            }
          }
        }
      }
    }
    long ret = 0;
    foreach (bit; 0 .. (1 << 10)) {
      if (popcnt(bit) <= k) {
        chmax(ret, dp[n.length][0][0][bit]);
        chmax(ret, dp[n.length][0][1][bit]);
        chmax(ret, dp[n.length][1][0][bit]);
        chmax(ret, dp[n.length][1][1][bit]);
      }
    }
    return ret;
  }

  long mia() { // a以上の最小の整数
    import core.bitop : popcnt;

    auto dp = new long[][][][](n.length + 1, 2, 2, 1 << 10);
    const long inf = 10L ^^ 18;
    foreach (i; 0 .. (n.length + 1)) {
      foreach (bit; 0 .. (1 << 10)) {
        dp[i][0][0][bit] = inf;
        dp[i][0][1][bit] = inf;
        dp[i][1][0][bit] = inf;
        dp[i][1][1][bit] = inf;
      }
    }
    dp[0][0][0][0] = 0; // ??
    void chmin(ref long l, long r) {
      l = min(l, r);
    }

    foreach (i; 0 .. n.length) {
      foreach (g; 0 .. 2) {
        foreach (z; 0 .. 2) {
          foreach (b; 0 .. (1 << 10)) {
            if (dp[i][g][z][b] < inf) {
              auto d = g ? 0 : n[i];
              for (int digit = d; digit < 10; digit++) {
                auto greater = g || (digit > d);
                auto zero = z || (digit > 0);
                auto bit = !zero ? b : (b | (1 << digit));
                chmin(dp[i + 1][greater][zero][bit], dp[i][g][z][b] * 10 + digit);
              }
            }
          }
        }
      }
    }
    long ret = inf;
    foreach (bit; 0 .. (1 << 10)) {
      if (popcnt(bit) <= k) {
        chmin(ret, dp[n.length][0][0][bit]);
        chmin(ret, dp[n.length][0][1][bit]);
        chmin(ret, dp[n.length][1][0][bit]);
        chmin(ret, dp[n.length][1][1][bit]);
      }
    }
    return ret;
  }

  writeln(min(a - maa(), mia() - a));
}

void rd(T...)(ref T x) {
  import std.stdio : readln;
  import std.string : split;
  import std.conv : to;

  auto l = readln.split;
  assert(l.length == x.length);
  foreach (i, ref e; x)
    e = l[i].to!(typeof(e));
}

Submission Info

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