C++程序 查找系列-1、2、11、26、47……的第N个项
给定数字N,任务是找到该系列的第N个项:
-1、2、11、26、47、74、……
示例:
输入: 3
输出: 11
解释:
当N = 3时,
第N个项 =((3 * N * N) -(6 * N)+2)
=((3 * 3 * 3) -(6 * 3)+2)
= 11
输入: 9
输出: 191
方法: 该给定序列的第N个项可以一般化为:
该序列的第N项是:((3 * N * N) -(6 * N)+2)
以下是上述问题的实现:
程序:
// CPP program to find N-th term of the series:
// 9, 23, 45, 75, 113, 159......
#include <iostream>;
using namespace std;
// calculate Nth term of series
int nthTerm(int N)
{
return ((3 * N * N) - (6 * N) + 2);
}
// Driver Function
int main()
{
// Get the value of N
int N = 3;
// Find the Nth term
// and print it
cout << nthTerm(N);
return 0;
}
// Java program to find N-th term of the series:
// 9, 23, 45, 75, 113, 159......
class GFG {
// calculate Nth term of series
static int nthTerm(int N)
{
return ((3 * N * N) - (6 * N) + 2);
}
// Driver code
public static void main(String[] args) {
int N = 3;
// Find the Nth term
// and print it
System.out.println(nthTerm(N));
}
}
// This code is contributed by bilal-hungund
# Python3 program to find N-th term
# of the series:
# 9, 23, 45, 75, 113, 159......
def nthTerm(N):
#calculate Nth term of series
return ((3 * N * N) - (6 * N) + 2);
# Driver Code
if __name__=='__main__':
n = 3
#Find the Nth term
# and print it
print(nthTerm(n))
# this code is contributed by bilal-hungund
// C# program to find N-th term of the series:
// 9, 23, 45, 75, 113, 159......
using System;
class GFG
{
// calculate Nth term of series
static int nthTerm(int N)
{
return ((3 * N * N) - (6 * N) + 2);
}
// Driver code
public static void Main()
{
int N = 3;
// Find the Nth term
// and print it
Console.WriteLine(nthTerm(N));
}
}
// This code is contributed by inder_verma
<?php
// PHP program to find N-th term of
// the series: 9, 23, 45, 75, 113, 159......
// calculate Nth term of series
function nthTerm(N)
{
return ((3 *N * N) -
(6 *N) + 2);
}
// Driver Code
// Get the value of N
N = 3;
// Find the Nth term
// and print it
echo nthTerm(N);
// This code is contributed by Raj
?>
<script>
//JavaScript 程序用于找出系列的第 N 个项:
//9、23、45、75、113、159 ......
//计算系列的第 N 个项
function nthTerm(N)
{
return ((3 * N * N) - (6 * N) + 2);
}
//Driver Function
//获取 N 的值
let N = 3;
//找到第 N 个项并打印出来
document.write(nthTerm(N));
// 这段代码由Surbhi Tyagi贡献
</script>```
输出:
11
时间复杂度: O(1)
空间复杂度 : O(1),因为使用不变量