"4 Values whose Sum is 0" 如果直接暴力枚举的话,其复杂度为$O(n^
原创 2022-11-03 15:19:36
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题意:四个元素个数相等的A,B,C,D,问a+b+c+d=0的个数$(a\in{A},b\in{B},c\in{C},d\in{D})$,$n<=10^3$ 所以 $n^4$???? 肯定不行的啊 用sum1处理出a+b的和 用sum2处理出c+d的和 然后枚举sum1,二分找sum2,求ans 然
原创 2021-07-26 22:48:29
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​​题目传送门​​【题意】题意很简单,给了n*4的矩阵,问有多少种情况满足每一列取一个某个数字,加起来为0.【解题思路】 Hash.【AC代码】#include <stdio.h>#include <string.h>#include <iostream>#include <algorithm>using namespace std;#define
原创 2022-04-20 10:10:16
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Description The SUM problem can be formulated as follows: given four lists A, B, C, D of integer values, compute how many quadruplet (a, b, c, d ) ∈ A
转载 2018-04-09 23:52:00
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4 Values whose Sum is 0Time Limit: 15000MSMemory Limit: 228000KTotal Submissions:
原创 2023-07-11 16:24:55
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哈希
原创 2023-02-23 10:07:17
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题目: POJ 2785 4 Values whose Sum is 0 ,哈哈,我们今天来看一道稍微简单的二分题嘛,这是选自POJ上的一道题,好了,我们一
原创 2024-04-19 11:36:21
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思路:分治法 枚举4组数O(n^4)绝对超时 因此可以使用分治的思想,将 4 组数分为两组,然后每组再分别
原创 2022-06-02 13:31:55
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这个题真是自己一下就想到的。不过在效率上比较低。4000MS+
原创 2023-07-27 18:47:34
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原创 2022-09-26 17:34:21
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The SUM problem can be formulated as follows: given four lists A, B, C, D of integer values, compute how many quadruplet (a, b, c, d ) ∈ A x B x C x D are such that a + b + c + d = 0 . In the followin...
原创 2021-07-09 15:14:23
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The SUM problem can be formulated as follows: given four lists A, B, C, D of integer values, compute how many quadruplet (a, b, c, d )...
原创 2021-09-02 11:44:25
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【题目链接】 http://poj.org/problem?id=2785 【题目大意】 给出四个数组,从每个数组中选出一个数,使得四个数相加为0,求方案数 【题解】 将a+b存入哈希表,反查-c-d 【代码】
转载 2017-01-19 14:05:00
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hash结构体struct Hash_map{ static const int mask=0x7fffff; int p[8388608],q[8388608]; void clear(){ for(int i=0;i<=mask;++i) q[i]=0; } int & operator [
原创 2022-08-05 17:03:53
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题面 The SUM problem can be formulated as follows: given four lists A, B, C, D of integer values, compute how many quadruplet (a, b, c, d ) ∈ A x B x C
转载 2020-04-06 12:32:00
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【题目链接】:click here~~【题目大意】:The SUM problem can be formulated as follows: given four lists A, B, C, D of integer values, compute how many quadruplet (a, b, c, d ) ∈ A x B x C x D are such that a +
原创 2022-07-29 21:38:12
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4 Values whose Sum is 0Time Limit: 15000MS Memory Limit: 228000KTotal Submissions: 20020 Accepted: 5977Case Time Limit: 5000MSDescriptionThe SUM problem
原创 2022-08-10 11:07:06
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DescriptionThe SUM problem can be formulated as follows: given four lists A, B, C, D of integer values, compute how many quadruplet (a, b, c, d ) ∈ A x B x C x D are such that a + b + c + d = 0 . In t
原创 2023-03-03 13:48:25
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灵活
原创 2022-08-17 15:25:24
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题意:要从四个数组中各选一个数,使得这四个数之和为0,求合法的方案数。分析:首先枚举A+B所有可能的值,排序。然后枚举所有-C-D的值在其中用二分法查找。 1 #include 2 #include 3 using namespace std; 4 5 const int maxn = 400...
转载 2015-02-04 19:59:00
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