Difference between revisions of "2019 Multi-University,Nowcoder Day 9"
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Solved by Xiejiadong. 00:47:16 (+) | Solved by Xiejiadong. 00:47:16 (+) | ||
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| + | 题意：给出 $a+b\;mod\; p$ 和 $ab\;mod\; p$ 的结果，求 $a$ 和 $b$ 。 | ||
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| + | 题解：可以从 $(a-b)^2=(a+b)^2-4ab$ 得到 $(a-b)^2$ ，利用二次剩余求得 $a-b$ ，再和差得到 $a$ 、 $b$ 。 | ||
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| + | F0RE1GNERS 的二次剩余板子需要特判 $b=0$ 的情况，会死循环。 | ||
== Problem C == | == Problem C == | ||
Revision as of 13:23, 15 August 2019
Problem A
Solved by Weaver_zhu. 04:10:16 (+)
Problem B
Solved by Xiejiadong. 00:47:16 (+)
题意：给出 $a+b\;mod\; p$ 和 $ab\;mod\; p$ 的结果，求 $a$ 和 $b$ 。
题解：可以从 $(a-b)^2=(a+b)^2-4ab$ 得到 $(a-b)^2$ ，利用二次剩余求得 $a-b$ ，再和差得到 $a$ 、 $b$ 。
F0RE1GNERS 的二次剩余板子需要特判 $b=0$ 的情况，会死循环。
Problem C
Solved by Kilo_5723. 04:46:30 (+1)
Problem D
Solved by Kilo_5723. 00:52:54 (+)
Problem E
Solved by Xiejiadong. 01:49:18 (+)
Problem F
Unsolved.
Problem G
Unsolved.
Problem H
Upsolved by Xiejiadong. (-11)
Problem I
Unsolved.
Problem J
Solved by Kilo_5723. 01:24:15 (+3)