1
var validateStackSequences = function (pushed, popped) {
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  let stack = [];
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  let j = 0;
4

5
  for (let i = 0; i < pushed.length; i++) {
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    stack.push(pushed[i]);
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    while (stack.length != 0 && popped[j] == stack[stack.length - 1]) {
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      stack.pop();
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      j++;
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    }
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  }
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  return stack.length < 1;
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};