###### tags: `C#`

# 資料結構

三維陣列

public static void Main()
	{
	
		int[,,] num = {
						{{33, 45, 67},{23, 71, 56},{55, 38, 66}},
						{{21, 9, 15},{38, 68, 18},{90, 101, 89}}
					  };
		int min = num[0,0,0];
		for(int i = 0; i < num.GetLength(0); i++)
		{
			for (int j = 0; j < num.GetLength(1); j++)
		     {
		        for (int z = 0; z < num.GetLength(2); z++)
		          {
		              //Response.Write(num[i, j, z].ToString());
		              if(min >= num[i, j, z])
		              {
		            		min = num[i, j, z];
		              }
		          }
		     }
		}
		 Console.Write(min.ToString());
		
	}
	

貪心演算法:假设商店老板需要找零n元钱，钱币的面额有：100元、50元、20元、5元、1元，如何找零使得所需钱币的数量最少？

public static void Main()
	{
		// your code goes here
		//第一个问题 找零

		//假设商店老板需要找零n元钱，钱币的面额有：100元、50元、20元、5元、1元，如何找零使得所需钱币的数量最少？ 
		int[] len = ChangeMoney(346);
		for (int i = 0; i < len.Length; i++){
			Console.Write(len[i]);
		}
		
	}
	
	public static int[]  ChangeMoney(int n){
		int[] money = new int[] {100, 50, 20, 5, 1};
		int[] change = new int[] {0, 0, 0, 0,0};
		for (int i = 0; i < money.Length; i++){
			if (n == 0)
				break;
			change[i] = n / money[i];
			n = n % money[i];
		}
		return change;
	}

動態規劃

public static void Main()
	{
		// your code goes here
		Console.Write(fib(4));
	}
    
	
   public static int fib(int n){
        int[] output = new int[1000];
		int result = output[n];
	 
		if (result == 0){
			if (n == 0)
				return 0;
			if (n == 1)
				return 1;
			else
				return (fib(n-1) + fib(n-2));
				
		}
		 output[n] = result;
		 return result;
	}

階乘

public static void Main()
	{
		// your code goes here
		factorial(5);
	}
	
	public static void factorial(int num){
		 int sum = 1;
		 
		 for(int i = 1; i < num + 1; i++){
		 	for(int j = i; j > 0; j--){
		 		sum = sum * j;
		 	}
		 	Console.Write(i + "!=" + sum + "\n");
		 	sum = 1;
		 }
	}