4 Values whose Sum is 0 Time Limit: 15000MS   Memory Limit: 228000K Total Submissions: 25615   Accepted: 7697 Case Time Limit: 5000MS Description The SUM problem can be formulated as follows: given four lists A, B, C, D of integer values, compute how…

4 Values whose Sum is 0 Time Limit: 15000MS   Memory Limit: 228000K Total Submissions: 21370   Accepted: 6428 Case Time Limit: 5000MS Description The SUM problem can be formulated as follows: given four lists A, B, C, D of integer values, compute how…

4 Values whose Sum is 0 Time Limit: 15000MS   Memory Limit: 228000K Total Submissions: 18221   Accepted: 5363 Case Time Limit: 5000MS Description The SUM problem can be formulated as follows: given four lists A, B, C, D of integer values, compute how…

2017-08-01 21:29:14 writer:pprp 参考:http://blog.csdn.net/piaocoder/article/details/45584763 算法分析:直接暴力复杂度过高,所以要用二分的方法,分成两半复杂度就会大大降低: 题目意思:给定4个n(1<=n<=4000)元素的集合 A.B.C.D ,从4个集合中分别选取一个元素a, b,c,d.求满足 a+b+c+d=0的个数 代码如下: //首先将前两列任意两项相加得到数组x,再将后两列任意两项相加取反得到…

问题分析 首先枚举a和b, 把所有a+b记录下来放在一个有序数组,然后枚举c和d, 在有序数组中查一查-c-d共有多少个.注意这里不可以直接用二分算法的那个模板,因为那个模板只能查找是否有某个数,一旦找到便退出.利用lower_bound,upper_bound比较方便,这两个函数就是用二分实现的,二者之差就是相等的那部分. 代码 #include<bits/stdc++.h> using namespace std; typedef long long LL; LL T, n; const…

题意:给你四组长度为\(n\)序列,从每个序列中选一个数出来,使得四个数字之和等于\(0\),问由多少种组成情况(仅于元素的所在位置有关). 题解:\(n\)最大可以取4000,直接暴力肯定是不行的,我们可以先对后两个数组\(c\)和\(d\),枚举他们每个元素的和,用一个新数组\(CD\)记录,然后再去枚举\(a\)和\(b\)的和,那么我们只要在\(CD\)中二分查找\(a\)和\(b\)的和的相反数就好了. 代码: #include <iostream> #include <cst…

4 Values whose Sum is 0 Time Limit: 15000MS Memory Limit: 228000K Total Submissions: 19322 Accepted: 5778 Case Time Limit: 5000MS Description The SUM problem can be formulated as follows: given four lists A, B, C, D of integer values, compute how man…

4 Values whose Sum is 0 题目链接:https://cn.vjudge.net/problem/UVA-1152 ——每天在线,欢迎留言谈论. 题目大意: 给定4个n(1<=n<=4000)元素的集合 A.B.C.D ,从4个集合中分别选取一个元素a, b,c,d.求满足 a+b+c+d=0的对数. 思路: 直接分别枚举 a,b,c,d ,坑定炸了.我们先枚举 a+b并储存,在B.C中枚举找出(-c-d)后进行比较即可. 亮点: 由于a+b,中会有值相等的不同组合,如果使…

4 Values whose Sum is 0 Time Limit: 15000MS   Memory Limit: 228000K Total Submissions: 25675   Accepted: 7722 Case Time Limit: 5000MS Description The SUM problem can be formulated as follows: given four lists A, B, C, D of integer values, compute how…

G - 4 Values whose Sum is 0 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 following, we assume that all…