playground java

java init
add
Revert "add"

This reverts commit 74d4fb513da92d938585f95241c5bdd4450a08e1.
Revert "playground java"

This reverts commit 01cb1a7d07d8d450c37bde2adcbae2ac63ba0deb.
[Java] [Solving Optimization Problems]

{Simple Algorithms, Numeric Optimizations}