[Code Interview Problem] Building a SuperStack

Build a Super Stack.
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Requirements:
- Print value of "peak" after each operation.
- n            : the number of operations
- POP       : get the value of "peak", if there is no more value after pop, then print "EMPTY"
- PUSH d : put the new value(d) after "peak", then print the value of "peak"
- INC x d : add the new value(d) from index 0 to x elements, then print the value of "peak"

- Example
  input   :
               8
               PUSH 1
               POP
               PUSH 3
               PUSH 4
               PUSH 5
               INC 3 1
               POP
               PUSH 9
  output :
               1
               EMPTY
               3
               4
               5
               6
               4
               9

 the values in the Super Stack
 peak       9
               5
 base       4



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Show Source code

import java.util.StringTokenizer;

public class SuperStack {
public static void main(String[] argv) {

String[] cmds = {"14", "PUSH 4", "POP", "PUSH 3", "PUSH 5", "PUSH 2"
, "INC 3 1", "POP", "PUSH 1", "INC 2 2", "PUSH 4"
, "POP", "POP", "PUSH 10", "PUSH 11"};

String cmd = null;

int[] stk = new int[100];
int here = -1;
int n = Integer.parseInt( cmds[0] );
for( int i=1; i<=n; i++ ) {
StringTokenizer st = new StringTokenizer( cmds[i], " " );
cmd = st.nextToken();

if( "POP".compareTo(cmd) == 0 ) {
if( here == 0 ) {
here--; // Do POP
System.out.println("EMPTY");
}
else {
here--; // Do POP
System.out.println(stk[here]);
}
} else if( "PUSH".compareTo(cmd) == 0 ) {
stk[++here] = Integer.parseInt(st.nextToken()); // Do PUSH
System.out.println(stk[here]);
} else if( "INC".compareTo(cmd) == 0 ) {
int t = Integer.parseInt(st.nextToken());
int d = Integer.parseInt(st.nextToken());

for( int k=0; k<t; k++ ) {
stk[k] = stk[k] + d;
}
System.out.println(stk[here]);
}
}
System.out.println("-Top---------------------------");
for( int i=here; i>=0; i-- ) {
System.out.println(stk[i]);
}
System.out.println("-Bottom------------------------");
}
}