Value of Pi(Π) up to 50 decimal places

Given a number N(where N <= 50), the task is to find the value of Pi (?) up to N decimals places.
Examples:

Input: N = 2 
Output: 3.14

Input: N = 10 
Output: 3.1415926536  

Approach:

1. The value of ? is calculated using acos() function which returns a numeric value between [-?, ?].

2. Since using acos(0.0) will return the value for 2*?. Therefore to get the value of ?: 

double pi = 2*acos(0.0);

3. Now the value obtained from above equation is estimated to N decimal digit as:

printf("%.*lf\n", N, pi);

Below is the implementation of the above approach:  

C++

// C++ program to calculate the
// value of pi up to n decimal
// places
#include "bits/stdc++.h"
using namespace std;

// Function that prints the
// value of pi upto N
// decimal places
void printValueOfPi(int N)
{

    // Find value of pi upto
    // using acos() function
    double pi = 2 * acos(0.0);

    // Print value of pi upto
    // N decimal places
    printf("%.*lf\n", N, pi);
}

// Driver Code
int main()
{
    int N = 45;

    // Function that prints
    // the value of pi
    printValueOfPi(N);
    return 0;
}

Java

import java.io.*;
import java.text.DecimalFormat;
// Java program to calculate the
// value of pi up to n decimal places
class GFG {

    // Function that prints the
    // value of pi upto N
    // decimal places
    static void printValueOfPi(int n)
    {

        // Find value of pi upto
        // using acos() function
        double pi = 2 * Math.acos(0.0);
        pi = Math.round(pi * Math.pow(10, n))
             / Math.pow(10, n);

          // Print value of pi upto
        // N decimal places
        System.out.println(pi);
    }

    // Driver Code
    public static void main(String[] args)
    {
        int N = 7;

        // Function that prints
        // the value of pi
        printValueOfPi(N);
    }
}

// This code is contributed by AnkitRai01

Python3

# Python3 program to calculate the
# value of pi up to n decimal places
from math import acos

# Function that prints the
# value of pi upto N
# decimal places
def printValueOfPi(N) :

    # Find value of pi upto
    # using acos() function
    b = '{:.' + str(N) + 'f}'
    pi= b.format(2 * acos(0.0))


    # Print value of pi upto
    # N decimal places
    print(pi);

# Driver Code
if __name__ == "__main__" :

    N = 43;

    # Function that prints
    # the value of pi
    printValueOfPi(N);

# This code is contributed by AnkitRai01

C#

// C# program to calculate the
// value of pi up to n decimal places
using System;

class GFG {

    // Function that prints the
    // value of pi upto N
    // decimal places
    static void printValueOfPi(int N)
    {

        // Find value of pi upto
        // using acos() function
        double pi = 2 * Math.Acos(0.0);

        // Print value of pi upto
        // N decimal places
        Console.WriteLine(pi);
    }

    // Driver Code
    public static void Main()
    {
        int N = 4;

        // Function that prints
        // the value of pi
        printValueOfPi(N);
    }
}

// This code is contributed by AnkitRai01

Javascript

<script>
    // Javascript program to calculate the
    // value of pi up to n decimal places

    // Function that prints the
    // value of pi upto N
    // decimal places
    function printValueOfPi(N)
    {

        // Find value of pi upto
        // using acos() function
        let pi = 2 * Math.acos(0.0);

        // Print value of pi upto
        // N decimal places
        document.write(pi.toFixed(4));
    }

    let N = 4;

    // Function that prints
    // the value of pi
    printValueOfPi(N);

// This code is contributed by divyesh072019.
</script>

Output:

3.1416

Time Complexity: O(1)
Auxiliary Space: O(1)