﻿// <copyright file="Problem018.cs">
//     Copyright (c) 2017 All rights reserved.
// </copyright>
// <clrversion>4.0.30319.42000</clrversion>
// <author>Alex H.-L. Chan</author>

using System;
using Common.Framework.Core.Enums;
using Common.Framework.Core.Logging;
using Common.Framework.Data.Managers;

namespace ProjectEuler.Problems
{
    /// <summary>
    /// Maximum path sum I
    /// -
    /// By starting at the top of the triangle below and moving to adjacent numbers on the row below, the maximum total from top to bottom is 23.
    /// 3
    /// 7 4
    /// 2 4 6
    /// 8 5 9 3
    /// That is, 3 + 7 + 4 + 9 = 23.
    /// Find the maximum total from top to bottom of the triangle below:
    /// 75
    /// 95 64
    /// 17 47 82
    /// 18 35 87 10
    /// 20 04 82 47 65
    /// 19 01 23 75 03 34
    /// 88 02 77 73 07 63 67
    /// 99 65 04 28 06 16 70 92
    /// 41 41 26 56 83 40 80 70 33
    /// 41 48 72 33 47 32 37 16 94 29
    /// 53 71 44 65 25 43 91 52 97 51 14
    /// 70 11 33 28 77 73 17 78 39 68 17 57
    /// 91 71 52 38 17 14 91 43 58 50 27 29 48
    /// 63 66 04 68 89 53 67 30 73 16 69 87 40 31
    /// 04 62 98 27 23 09 70 98 73 93 38 53 60 04 23
    /// NOTE: As there are only 16384 routes, it is possible to solve this problem by trying every route.
    /// However, Problem 67, is the same challenge with a triangle containing one-hundred rows; it cannot be solved by brute force, and requires a clever method! ;o)
    /// </summary>
    public class Problem018 : Problem
    {
        private int _maxPathSum;

        public Problem018()
        {
            Source = AppConfigParameters
                .Keys[ProjectEulerConstants.Problem018Key]
                .Collection[ProjectEulerConstants.Problem018SourceKey];
        }

        public Problem018(string source)
        {
            Source = source;
        }

        public string Source { get; set; }

        public override dynamic Solve()
        {
            var flatFileDataManager = new FlatFileDataManager(
                BuiltInType.Integer,
                CollectionType.ArrayJagged,
                DelimiterType.Space,
                Source);
            var triangle = flatFileDataManager.Input;
            for (var i = triangle.GetLength(0) - 2; i >= 0; i--)
            {
                for (var j = 0; j <= i; j++)
                {
                    triangle[i][j] +=
                        Math.Max(triangle[i + 1][j], triangle[i + 1][j + 1]);
                }
            }

            _maxPathSum = triangle[0][0];

            return _maxPathSum;
        }

        protected override void LogResult()
        {
            ResultMessage =
                "The maximum total from top to bottom of the provided triangle [" +
                Source +
                "] is [" +
                _maxPathSum +
                "].";
            LogManager.Instance().LogResultMessage(ResultMessage);
        }
    }
}
