real-shooter/Assets/Scripts/Managers/MapManager.cs

using System.Collections.Generic;
using UnityEngine;

public class MapManager : MonoBehaviour
{
    private static MapManager instance;
    public static MapManager Instance => instance;
    private static List<NavPoint> navPoints = new List<NavPoint>();
    private static Dictionary<int, NavPoint> iDToNavPoint = new Dictionary<int, NavPoint>();
    public static List<NavPoint> NavPoints { get => navPoints; private set => navPoints = value; }
    public static Dictionary<int, NavPoint> IDToNavPoint { get => iDToNavPoint; private set => iDToNavPoint = value; }

    private void Awake()
    {
        if (instance is null)
            instance = this;
        else
        {
            Destroy(gameObject);
            Debug.LogError("Only 1 Instance");
        }
    }

    private void Start()
    {
        var navPointSet = GameObject.Find("NavPoint Set");
        var count = navPointSet.transform.childCount;
        for (int i=0; i < count; i++)        
            NavPoints.Add(navPointSet.transform.GetChild(i)
                .gameObject.GetComponent<NavPoint>());

        NavPointSetToID();
    }

    private void NavPointSetToID()
    {
        int i = 0;
        foreach (var navPoint in NavPoints)
        {
            IDToNavPoint.Add(i, navPoint);
            navPoint.PointId = i;
            i++;
        }
    }

    public static void AddDeathAttributeToPoints(int startPoint, int endPoint, 
        float allDistance, float remainingDistance)
    {
        var startNavPoint = IDToNavPoint[startPoint];
        var endNavPoint = IDToNavPoint[endPoint];
        float coef; 
        try
        {
            coef = remainingDistance / allDistance;
        }
        catch (System.ArithmeticException)
        {
            Debug.LogError("Path Length is zero");
            return;
        }
        startNavPoint.DeathAttr += 1 - coef;
        endNavPoint.DeathAttr += coef;
    }
}