找到数的方式将数分成四份，这样 a = c，b = d
原文:https://www . geeksforgeeks . org/find-the-number-of-way-to-number-division-to-a-c-and-b-d/
给定一个数字 N 。求数的方法把一个数分成四份(a，b，c，d)，这样 a = c，b = d，a 不等于 b. 例:
输入: N = 6 输出: 1 解释:四个部分为{1，2，1，2} 输入: N = 20 输出: 4 解释:可能的方式有{1，1，9，9}、{2，2，8，8}、{3，3，7，7}和{4，4，8 }
逼近: 如果给定的 N 为奇数，则答案为 0，因为四个部分之和不会是偶数。 如果 n 能被 4 整除，那么答案就是 n/4 -1(这里 a 等于 b 是可能的，所以减去那个可能性)，否则就是 n/4。 以下是上述方法的实现:
C++
// C++ implementation for above approach
#include <bits/stdc++.h>
using namespace std;
// Function to find the number of ways to divide
// N into four parts such that a = c and b = d
int possibleways(int n)
{
if (n % 2 == 1)
return 0;
else if (n % 4 == 0)
return n / 4 - 1;
else
return n / 4;
}
// Driver code
int main()
{
int n = 20;
cout << possibleways(n);
return 0;
}
Java 语言(一种计算机语言，尤用于创建网站)
// Java implementation for above approach
class GFG
{
// Function to find the number of ways to divide
// N into four parts such that a = c and b = d
static int possibleways(int n)
{
if (n % 2 == 1)
return 0;
else if (n % 4 == 0)
return n / 4 - 1;
else
return n / 4;
}
// Driver code
public static void main(String[] args)
{
int n = 20;
System.out.println(possibleways(n));
}
}
// This code contributed by Rajput-Ji
Python 3
# Python3 implementation for above approach
# Function to find the number of ways
# to divide N into four parts
# such that a = c and b = d
def possibleways(n):
if (n % 2 == 1):
return 0;
elif (n % 4 == 0):
return n // 4 - 1;
else:
return n // 4;
# Driver code
n = 20;
print(possibleways(n));
# This code is contributed by mits
C
// C# implementation for above approach
class GFG
{
// Function to find the number of ways to divide
// N into four parts such that a = c and b = d
static int possibleways(int n)
{
if (n % 2 == 1)
return 0;
else if (n % 4 == 0)
return n / 4 - 1;
else
return n / 4;
}
// Driver code
static void Main()
{
int n = 20;
System.Console.WriteLine(possibleways(n));
}
}
// This code is contributed by mits
服务器端编程语言（Professional Hypertext Preprocessor 的缩写）
<?php
// PHP implementation for above approach
// Function to find the number of ways to divide
// N into four parts such that a = c and b = d
function possibleways($n)
{
if ($n % 2 == 1)
return 0;
else if ($n % 4 == 0)
return $n / 4 - 1;
else
return $n / 4;
}
// Driver code
$n = 20;
echo possibleways($n);
// This code is contributed by ajit
?>
java 描述语言
<script>
// java script implementation for above approach
// Function to find the number of ways to divide
// N into four parts such that a = c and b = d
function possibleways(n)
{
if (n % 2 == 1)
return 0;
else if (n % 4 == 0)
return n / 4 - 1;
else
return n / 4;
}
// Driver code
let n = 20;
document.write( possibleways(n));
// This code is contributed by Gottumukkala Bobby
</script>
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