budget-allocation-problem

Usage

$ stack exec $(basename `pwd`)-exe < sample-input.json
{
  "balances": [
    {
      "amount": 188301,
      "district": "Palolene"
    },
    {
      "amount": 137500,
      "district": "Southern Palolene"
    },
    {
      "amount": 368000,
      "district": "Lakos"
    }
  ],
  "deficits": [
    {
      "amount": 168500,
      "billName": "An Act to Construct the Great Wall of Malodivo"
    },
    {
      "amount": 31258,
      "billName": "An Act to Construct Shelters for the Homeless"
    },
    {
      "amount": 4500,
      "billName": "An Act to Fund the Development of Longer-Lasting Paper"
    },
    {
      "amount": 83543,
      "billName": "An Act to Increase Retirement Benefits for Veterans"
    }
  ],
  "contributions": [
    {
      "billName": "An Act to Construct the Great Wall of Malodivo",
      "funds": [
        {
          "amount": 1000,
          "district": "Palolene"
        },
        {
          "amount": 500,
          "district": "Southern Palolene"
        },
        {
          "amount": 30000,
          "district": "Lakos"
        }
      ]
    },
    {
      "billName": "An Act to Construct Shelters for the Homeless",
      "funds": [
        {
          "amount": 2742,
          "district": "Palolene"
        },
        {
          "amount": 5000,
          "district": "Southern Palolene"
        },
        {
          "amount": 1000,
          "district": "Lakos"
        }
      ]
    },
    {
      "billName": "An Act to Fund the Development of Longer-Lasting Paper",
      "funds": [
        {
          "amount": 7500,
          "district": "Palolene"
        },
        {
          "amount": 2000,
          "district": "Southern Palolene"
        },
        {
          "amount": 0,
          "district": "Lakos"
        }
      ]
    },
    {
      "billName": "An Act to Increase Retirement Benefits for Veterans",
      "funds": [
        {
          "amount": 457,
          "district": "Palolene"
        },
        {
          "amount": 5000,
          "district": "Southern Palolene"
        },
        {
          "amount": 1000,
          "district": "Lakos"
        }
      ]
    }
  ]
}

Test

$ stack test --fast

Assumptions

1. The absence of a default means that there's no allocation for that category

Limitations

1. Due to rounding, a bill might fall short of funds even when a single district can fund it

Improvements

1. Ensure that a bill is fully funded when possible, maybe by doing another round of allocation
2. Factor out .Internal modules to hide private names from the API, but sill making them available for testing