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class Solution {
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  public boolean validateStackSequences(int[] pushed, int[] popped) {
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    Stack<Integer> st = new Stack<>(); // Create a stack
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    int j = 0; // Intialise one pointer pointing on popped array
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    for (int val : pushed) {
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      st.push(val); // insert the values in stack
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      while (!st.isEmpty() && st.peek() == popped[j]) { // if st.peek() values equal to popped[j];
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        st.pop(); // then pop out
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        j++; // increment j
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      }
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    }
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    return st.isEmpty(); // check if stack is empty return true else false
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  }
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}