原题链接 思路:哈希存入相反数 注意:HDU不支持long long要使用__int64 #include<cstdio> #include<cstring> #define mod 401704//开到所有数据十倍大左右 using namespace std; bool flag[mod]; __int64 m[][],hash[mod]; int judge(__int64 x) { int s=x%mod; ) s+=mod;//将负数转正 /*while(x<0)…

给定五个集合.问是否能从五个集合各取一个元素,使得元素之和为0. 这道题有两种做法,一种是哈希,然而之前没写过哈希.....比赛后从大神那copy了一份. 这里说还有一种. 对于这五个集合分为三组.1,2组求和为一组,3,4组求和分为一组,5为一组. 那么如今转化为了是否能从前两组中各取一个元素.使得这两个值和为第三组一个元素的相反数. 那么对于第一组我们升序排序.第二组我们降序排序. 对于第三组里的任一元素,假如第一组队首加第二组队首之和大于第三组的元素.那么第二组游标往后移一位,反之第一组移…

Trouble Time Limit: 5000MS   Memory Limit: 32768KB   64bit IO Format: %I64d & %I64u Submit Status Description Hassan is in trouble. His mathematics teacher has given him a very difficult problem called 5-sum. Please help him. The 5-sum problem is def…

Trouble Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 3526    Accepted Submission(s): 1113 Problem Description Hassan is in trouble. His mathematics teacher has given him a very difficult pro…

Trouble Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 5681    Accepted Submission(s): 1570 Problem Description Hassan is in trouble. His mathematics teacher has given him a very difficult pro…

Trouble Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 5388    Accepted Submission(s): 1494 Problem Description Hassan is in trouble. His mathematics teacher has given him a very difficult pro…

题目:click here 题意: 给定5组数据,每组数据选择一个数,看是否能找到5个数的和为零. 分析: 千万不要~~T~~ 普通线性查找: #include <iostream> #include <cstdio> #include <cstring> #include <algorithm> using namespace std; typedef long long ll; const int INF = 0x3f3f3f3f; ; int t, n…

Hassan is in trouble. His mathematics teacher has given him a very difficult problem called 5-sum. Please help him. The 5-sum problem is defined as follows: Given 5 sets S_1,...,S_5 of n integer numbers each, is there a_1 in S_1,...,a_5 in S_5 such t…

题目大意:原题链接 给定平面上的N个点,求出这些点一共可以构成多少个正方形. 解题思路: 若正方形为ABCD,A坐标为(x1, y1),B坐标为(x2, y2),则很容易可以推出C和D的坐标.对于特定的A和B坐标,C和D可以在线段AB的上面或者下面,即有两种情况.           根据构造三角形全等可以得知(很简单,注意下细节,不要把坐标弄混就行) CD在AB上面x3=x2+(y1-y2),y3=y2+(x2-x1);    x4=x1+(y1-y2),y4=y1+(x2-x1); CD在A…

题目传送门 题意:5个集合,每个集合最多200个数字,问是否每个集合挑一个数加起来和为0. 分析:显然n^5的程序果断超时,甚至n^3logn的二分也过不了.想n^3的方法,既然判断有没有,那么可以将两个两个的集合合并成两个大集合,再枚举最后一个集合,两个大集合排完序之后一个指针从开头最小开始,另一个从最大的开始,>0,大指针往左移,<0,小指针往右移,那么可以在线性时间求解,这贪心方法很巧妙! 另一种做法算是暴力+优化了,哈希表储存一个两个集合合并后大集合的数字,n^3暴力询问是否哈希表内存…