auto commit

2018-09-05 17:22:45 +08:00
parent 5fe72c31d8
commit a015b11038
4 changed files with 13 additions and 8 deletions
--- a/notes/剑指
+++ b/notes/剑指
@ -1433,7 +1433,8 @@ public boolean IsPopOrder(int[] pushSequence, int[] popSequence) {
    Stack<Integer> stack = new Stack<>();
    for (int pushIndex = 0, popIndex = 0; pushIndex < n; pushIndex++) {
        stack.push(pushSequence[pushIndex]);
-        while (popIndex < n && stack.peek() == popSequence[popIndex]) {
+        while (popIndex < n && !stack.isEmpty() 
+                && stack.peek() == popSequence[popIndex]) {
            stack.pop();
            popIndex++;
        }