MPI_PI

Caculate PI using MPI with 3 differend methods

Author: KiwenLau

Method 1: using trapezoid rule

f(x)=(1-x^2)^0.5, so PI/4 is the integral of f(x) from 0 to 1. Then PI can be easily caculated using trapezoid rule.

Method 2: using trapezoid rule

f(x)=4/(1+x^2), so PI is the integral of f(x) from 0 to 1. Then PI can be easily caculated using trapezoid rule.

Method 3: using Monte Carlo method