嘟嘟嘟 很简单的折半搜索. 把式子变一下型,得到\(a + b = d - c\). 然后枚举\(a, b\),存到\(map\)里,再枚举\(c, d\)就好了. \(map\)以\(a,b\)两数之和为下标.为了判重,\(map\)的第二个参数是一个\(vector\),\(vector\)里面又存了两个数\(a, b\). 这样先\(O(n ^ 2)\)跑一边\(a, b\)之和,存到\(map\)里,然后从大到小枚举\(d\)和\(c\),遍历\(map\)中\(d - c\)的\(ve…

题目来自:http://218.5.5.242:9018/JudgeOnline/problem.php?id=1278 题目描述 给你一个整数的集合S(里面所有的整数均不相同),请你找出最大的 d,使得 a + b + c = d.在这里a,b,c,d均为S中的数且a,b,c,d是不同的数. 输入 每组测试资料的第一行有1个整数 n(1 <= n <= 1000),代表S中元素的个数.接下来的n行,每行有一个整数xi,代表S中的各元素.-536870912 <= xi <= +5…

Sumsets Time Limit: 2000MS   Memory Limit: 200000K Total Submissions: 11892   Accepted: 4782 Description Farmer John commanded his cows to search for different sets of numbers that sum to a given number. The cows use only numbers that are an integer…

Sumsets http://acm.hdu.edu.cn/showproblem.php?pid=2709 Problem Description Farmer John commanded his cows to search for different sets of numbers that sum to a given number. The cows use only numbers that are an integer power of 2. Here are the possi…

Sumsets Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 10593   Accepted: 2890 Description Given S, a set of integers, find the largest d such that a + b + c = d where a, b, c, and d are distinct elements of S. Input Several S, each cons…

Sumsets Time Limit: 6000/2000 MS (Java/Others)     Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 2159     Accepted Submission(s): 875 Problem Description Farmer John commanded his cows to search for different sets of numbers that sum…

                                                                                                 Sumsets Time Limit: 2000MS   Memory Limit: 200000K Total Submissions: 16876   Accepted: 6678 Description Farmer John commanded his cows to search for dif…

1677: [Usaco2005 Jan]Sumsets 求和 Time Limit: 5 Sec  Memory Limit: 64 MBSubmit: 570  Solved: 310[Submit][Status] Description Farmer John commanded his cows to search for different sets of numbers that sum to a given number. The cows use only numbers th…

Sumsets Time Limit: 2000MS   Memory Limit: 200000K Total Submissions: 15293   Accepted: 6073 Description Farmer John commanded his cows to search for different sets of numbers that sum to a given number. The cows use only numbers that are an integer…

Sumsets Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 9997   Accepted: 2736 Description Given S, a set of integers, find the largest d such that a + b + c = d where a, b, c, and d are distinct elements of S. Input Several S, each consi…