给定级别N,任务是找到在给定级别上出现的所有交替Pascal三角形中的整数之和。
修改后的Pascal三角形有5个等级,如下所示。
1
-1 1
1 -2 1
-1 3 -3 1
1 -4 6 -4 1
例子:
Input: N = 1
Output: 1
Input: N = 2
Output: 0
方法:正如我们可以看到的,对于偶数级,和为0,对于奇数级,除了1和也为0。因此最多可以有2种情况:
- 如果L = 1,则答案为1。
- 否则,答案将始终为0。
下面是上述方法的实现:
C++
// C++ program to calculate sum of
// all the numbers present at given
// level in an Modified Pascal’s triangle
#include
using namespace std;
// Function to calculate sum
void ans(int n)
{
if (n == 1)
cout << "1";
else
cout << "0";
}
// Driver Code
int main()
{
int n = 2;
ans(n);
return 0;
}
Java
// Java program to calculate sum of
// all the numbers present at given
// level in an Modified Pascal's triangle
class GFG
{
// Function to calculate sum
static void ans(int n)
{
if (n == 1)
System.out.println("1");
else
System.out.println("0");
}
// Driver Code
public static void main(String[] args)
{
int n = 2;
ans(n);
}
}
// This code is contributed by 29AjayKumar
Python3
# Python3 program to calculate sum of
# all the numbers present at given
# level in an Modified Pascal’s triangle
# Function to calculate sum
def ans(n) :
if (n == 1) :
print("1",end="");
else :
print("0",end="");
# Driver Code
if __name__ == "__main__" :
n = 2;
ans(n);
# This code is contributed by AnkitRai01
C#
// C# program to calculate sum of
// all the numbers present at given
// level in an Modified Pascal's triangle
using System;
class GFG
{
// Function to calculate sum
static void ans(int n)
{
if (n == 1)
Console.WriteLine("1");
else
Console.WriteLine("0");
}
// Driver Code
public static void Main(String[] args)
{
int n = 2;
ans(n);
}
}
// This code is contributed by 29AjayKumar
Javascript
输出:
0
时间复杂度: O(1)