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题目链接 Problem Description HazelFan wants to build a rooted tree. The tree has n nodes labeled 0 to n−1, and the father of the node labeled i is the nod 阅读全文
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题目链接 Problem Description The center coordinate of the circle C is O, the coordinate of O is (0,0) , and the radius is r.P and Q are two points not out 阅读全文
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题目链接 Problem Description As we know, Rikka is poor at math. Yuta is worrying about this situation, so he gives Rikka some math tasks to practice. Ther 阅读全文
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题目链接 Problem Description Sdjpx is a powful man,he controls a big country.There are n soldiers numbered 1~n(1<=n<=3000).But there is a big problem for 阅读全文
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题目链接 Problem Description Give you an array A[1..n]of length n. Let f(l,r,k) be the k-th largest element of A[l..r].Specially , f(l,r,k)=0 if r−l+1<k.G 阅读全文
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题目链接 Problem Description Give you an array A[1..n]，you need to calculate how many tuples (i,j,k) satisfy that (i<j<k) and ((A[i] xor A[j])<(A[j] xor A 阅读全文
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题目链接 Problem Description As to a permutation p1,p2,⋯,pn from 1 to n, it is uncomplicated for each 1≤i≤n to calculate (li,ri) meeting the condition tha 阅读全文
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题目链接 Problem Description There is a tree with n nodes, each of which has a type of color represented by an integer, where the color of node i is ci.Th 阅读全文
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题目链接 Problem Description sd0061, the legend of Beihang University ACM-ICPC Team, retired last year leaving a group of noobs. Noobs have no idea how to 阅读全文
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题目链接 Problem Description Once upon a time Matt went to a small town. The town was so small and narrow that he can regard the town as a pivot. There we 阅读全文