Add depth_first_search Java Code
Add depth_first_search Java Code

Resolved #2904
ZoranPandovski/al-go-rithms,ZoranPandovski/al-go-rithms,ZoranPandovski/al-go-rithms,ZoranPandovski/al-go-rithms,ZoranPandovski/al-go-rithms,ZoranPandovski/al-go-rithms,ZoranPandovski/al-go-rithms,ZoranPandovski/al-go-rithms,ZoranPandovski/al-go-rithms,ZoranPandovski/al-go-rithms,ZoranPandovski/al-go-rithms,ZoranPandovski/al-go-rithms,ZoranPandovski/al-go-rithms,ZoranPandovski/al-go-rithms,ZoranPandovski/al-go-rithms,ZoranPandovski/al-go-rithms,ZoranPandovski/al-go-rithms,ZoranPandovski/al-go-rithms,ZoranPandovski/al-go-rithms,ZoranPandovski/al-go-rithms