栈（stack）是先进后出的数据结构。单调栈在入栈时通过一定规则保持栈内元素有序（单调递增或单调递减），从而把「找左侧/右侧第一个更大/更小元素」从 O(n²) 降到 O(n)。
"Even the risk of that doesn't stop people from perpetrating fraud," Elahi marvelled.
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"This sort of semiconductor would go on to be in the 5G tower in which you get your mobile phone signal, it's going to be in the car charger you plug an EV into, it's going to be in the latest planes."，详情可参考搜狗输入法2026
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At least 15 people have been killed and others injured after a Bolivian air force cargo plane crashed in the western city of El Alto, the country's authorities say.