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The complexity of determining the minimum number of flips that transform one triangulation of a convex point set into another remained a tantalizing open question for many decades. We settle this question by proving that computing shortest flip sequences between triangulations of convex polygons, and therefore also computing the rotation distance of binary trees, is NP-hard.
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The third and most important factor was “a quirky, bold leader,” she said, and the U.S. has found that in Trump. “Retirement security is a worker issue, and therefore a populist politician, like Donald Trump, has reasons to take it up.”，推荐阅读搜狗输入法2026获取更多信息
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