最強最速アルゴリズマー養成講座P43より

gistfile1.d

import std.stdio;
import std.algorithm;
import std.range;

void main()
{
  auto capacities = [20, 30];
  auto bottles = [5, 8];
  auto fromId = [0];
  auto toId = [1];
  writeln((new KiwiJuiceEasy()).thePouring(capacities, bottles, fromId, toId));
}

class KiwiJuiceEasy
{
  int[] thePouring(int[] capacities, int[] bottles, int[] fromId, int[] toId)
  {
    foreach (ids; zip(fromId, toId)) {
      auto sum = bottles[ids[0]] + bottles[ids[1]];
      bottles[ids[1]] = min(sum, capacities[ids[1]]);
      bottles[ids[0]] = sum - bottles[ids[1]];
    }

    return bottles;
  }

  unittest
  {
    auto capacities = [20, 30];
    auto bottles    = [5, 8];
    auto fromId     = [0];
    auto toId       = [1];
    auto result     = [0, 13];
    assert(result == (new KiwiJuiceEasy()).thePouring(capacities, bottles, fromId, toId));
  }

  unittest
  {
    auto capacities = [10, 10];
    auto bottles    = [5, 8];
    auto fromId     = [0];
    auto toId       = [1];
    auto result     = [3, 10];
    assert(result == (new KiwiJuiceEasy()).thePouring(capacities, bottles, fromId, toId));
  }

  unittest
  {
    auto capacities = [30, 20, 10];
    auto bottles    = [10, 5, 5];
    auto fromId     = [0, 1, 2];
    auto toId       = [1, 2, 0];
    auto result     = [10, 10, 0];
    assert(result == (new KiwiJuiceEasy()).thePouring(capacities, bottles, fromId, toId));
  }

  unittest
  {
    auto capacities = [14, 35, 86, 58, 25, 62];
    auto bottles    = [6, 34, 27, 38, 9, 60];
    auto fromId     = [1, 2, 4, 5, 3, 3, 1, 0];
    auto toId       = [0, 1, 2, 4, 2, 5, 3, 1];
    auto result     = [0, 14, 65, 35, 25, 35];
    assert(result == (new KiwiJuiceEasy()).thePouring(capacities, bottles, fromId, toId));
  }

  unittest
  {
    auto capacities = [700000, 800000, 900000, 1000000];
    auto bottles    = [478478, 478478, 478478, 478478];
    auto fromId     = [2, 3, 2, 0, 1];
    auto toId       = [0, 1, 1, 3, 2];
    auto result     = [0, 156956, 900000, 856956];
    assert(result == (new KiwiJuiceEasy()).thePouring(capacities, bottles, fromId, toId));
  }
}