import { useState, useEffect, useRef } from "react";
// Usage
function App() {
  // State value and setter for our example
  const [count, setCount] = useState(0);
  // Get the previous value (was passed into hook on last render)
  const prevCount = usePrevious(count);
  // Display both current and previous count value
  return (
    <div>
      <h1>
        Now: {count}, before: {prevCount}
      </h1>
      <button onClick={() => setCount(count + 1)}>Increment</button>
    </div>
  );
}
// Hook
function usePrevious(value) {
  // The ref object is a generic container whose current property is mutable ...
  // ... and can hold any value, similar to an instance property on a class
  const ref = useRef();
  // Store current value in ref
  useEffect(() => {
    ref.current = value;
  }, [value]); // Only re-run if value changes
  // Return previous value (happens before update in useEffect above)
  return ref.current;
}

interface Task {
  id: number;
  title: string;
  completed: boolean;
}

class TaskManager {
  private tasks: Task[] = [];

  constructor() {}

  addTask(title: string) {
    const taskId = this.tasks.length + 1;
    const task: Task = {
      id: taskId,
      title,
      completed: false,
    };
    this.tasks.push(task);
  }

  markTaskAsComplete(taskId: number) {
    const task = this.tasks.find((task) => task.id === taskId);
    if (task) {
      task.completed = true;
    }
  }

  markTaskAsIncomplete(taskId: number) {
    const task = this.tasks.find((task) => task.id === taskId);
    if (task) {
      task.completed = false;
    }
  }

  listTasks() {
    console.log('Tasks:');
    this.tasks.forEach((task) => {
      console.log(`${task.id}. [${task.completed ? 'X' : ' '}] ${task.title}`);
    });
  }
}

// Example usage:
const taskManager = new TaskManager();
taskManager.addTask('Buy groceries');
taskManager.addTask('Pay bills');
taskManager.addTask('Clean the house');
taskManager.listTasks();

// Output:
// Tasks:
// 1. [ ] Buy groceries
// 2. [ ] Pay bills
// 3. [ ] Clean the house

// theme.ts
import { createTheme } from '@mui/material/styles';

const theme = createTheme({
  typography: {
    h1: {
      fontSize: '2rem',
      fontWeight: 700,
      lineHeight: 1.3
    },
    h2: {
      fontSize: '1.625rem',
      fontWeight: 700,
      lineHeight: 1.35
    },
    h3: {
      fontSize: '1.375rem',
      fontWeight: 700,
      lineHeight: 1.4
    },
    h4: {
      fontSize: '1.125rem',
      fontWeight: 700,
      lineHeight: 1.45
    },
    h5: {
      fontSize: '1rem',
      fontWeight: 700,
      lineHeight: 1.5
    },
    h6: {
      fontSize: '0.875rem',
      fontWeight: 700,
      lineHeight: 1.5
    },
  },
});

function removeElement(nums: number[], val: number): number {
    let zeroStartIndex = 0;
    for(let i = 0; i < nums.length; i++) {
        if(nums[i] !== val) {
            nums[zeroStartIndex] = nums[i];
            zeroStartIndex++;
        }
    }
    return zeroStartIndex;
};

function binarySearch(nums: number[], target: number): number {
    let left = 0;
    let right = nums.length - 1;

    while (left <= right) {
        const mid = left + Math.floor((right - left) / 2);

        if (nums[mid] === target) {
            return mid;
        } else if (nums[mid] < target) {
            left = mid + 1;
        } else {
            right = mid - 1;
        }
    }

    return left;
}

function searchInsert(nums: number[], target: number): number {
    return binarySearch(nums, target);
};

class DFS
{
   public dfs(G: DFSGraph, startVert: number)
   {
       let visited: boolean[] = Array<boolean>();
       // Pre-populate array:
       for(let i = 0; i < G.size; i++)
       {
           visited.push(false);
       }

       let s: number[] = new Array();

       visited[startVert] = true;

       s.push(startVert);

       while(s.length > 0)
       {
           const v = s.pop();
           for(let adjV of G.adj[v])
           {
               if(!visited[adjV])
               {
                   visited[adjV] = true;
                   s.push(adjV);
               }
           }
       }
   }

   public dfsRecursive(G: DFSGraph, startVert: number)
   {
       let visited: boolean[] = Array<boolean>();
       // Pre-populate array:
       for(let i = 0; i < G.size; i++)
       {
           visited.push(false);
       }
       this.dfsAux(G, startVert, visited);
   }

   private dfsAux(G: DFSGraph, v: number, visited: boolean[])
   {
       visited[v] = true;
       for(let adjV of G.adj[v])
       {
           if(!visited[adjV])
           {
               // this.foo(); // Something can happen before the visit.
               this.dfsAux(G, adjV, visited);
               // this.bar(); // Something can happen after the visit.
           }
       }
   }
}