Discord says facial scans never leave the user's device and IDs are only used to check a person's age, then deleted.
暴力做法是对每个位置向右扫描找第一个更大值，O(n²)。可抽象为：元素像一排人，身高为数值。当前人「下一个更大」= 他右侧第一个没被挡住的人（比当前矮的都被挡住）。单调栈用 O(n) 维护「右侧候选更大值」：倒序遍历，弹掉 ≤ 当前的，栈顶即答案，再入栈当前值。
，详情可参考同城约会
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Model Agreement
handling, but they did allow a single operator to handle a lot of documents.