Stack for Min function implementation

Package Structure. stack_queue; import java. util. Stack;/*** defines the data structure of the stack. A Min function must be added to obtain the minimum element of the stack. The time complexity of the min, push, and pop functions is O (1 ). ** @ Author toy **/public class stack_min {stack <integer> S = new stack <integer> (); stack <integer> mins = new stack <integer> (); public void push (INT d) {S. push (d); If (mins. isempty () {mins. push (0);} else {int minindex = mins. peek (); If (d <S. get (minindex) {mins. push (S. size ()-1);} else {mins. push (minindex) ;}} public int POP () {If (S. isempty () {system. out. println ("Empty stack"); Return-1;} else {mins. pop (); Return S. pop () ;}} public int min () {If (mins. isempty () {system. out. println ("Empty stack"); Return-1;} else {int minindex = mins. peek (); Return S. get (minindex) ;}}/*** @ Param ARGs */public static void main (string [] ARGs) {int [] A = new int [] {3, 4, 2, 5, 1, 6}; stack_min S = new stack_min (); For (INT I = 0; I <. length; I ++) {S. push (A [I]);} system. out. println (S. min (); S. pop (); S. pop (); system. out. println (S. min (); S. pop (); S. pop (); system. out. println (S. min ());}}