主要是要知道它对于等差数列的定义,单个数也可以作为等差数列且一定满足题意,另外就是要算清楚区间与区间的关系,考虑两大类情况,一种是d1区间和d2区间连在一起,另外一种情况就是其余情况. #include<iostream> #include<cstdio> #include<cstring> #define MAXN 100005 long long num[MAXN]; bool tag[MAXN]; using namespace std; long long ge…

http://acm.hdu.edu.cn/showproblem.php?pid=5400 Arithmetic Sequence Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 1151    Accepted Submission(s): 501 Problem Description A sequence b1,b2,⋯,bn a…

Problem Description A sequence b1,b2,⋯,bn are called (d1,d2)-arithmetic sequence ≤i≤n) such that ≤j<i),bj+=bj+d1 and =bj+d2. Teacher Mai has a sequence a1,a2,⋯,an. He wants to know how many intervals [l,r](≤l≤r≤n) there are that al,al+,⋯,ar are (d1,d…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=5400 水题 #include<stdio.h> typedef long long LL; const int MAXN = 1e5; LL cnt( int x ){ )/; } int main(){ int n; int d1, d2; int flag; int ct; long long ans; int a[MAXN]; while(~scanf("%d %d %d"…

Description There is a curious man called Matt. One day, Matt's best friend Ted is wandering on the non-negative half of the number line. Matt finds it interesting to know the maximal speed Ted may reach. In order to do so, Matt takes records of Ted'…

Matt has N friends. They are playing a game together.Each of Matt's friends has a magic number. In the game, Matt selects some (could be zero) of his friends. If the xor (exclusive-or) sum of the selected friends'magic numbers is no less than M , Mat…

http://acm.hdu.edu.cn/showproblem.php?pid=1077 很明显这样的圆,必定有两个点在边界上.n平方枚举圆,再n立方暴力判断.由于没有给T,所以不知道行不行.…

题目传送门 题意:问有多少个区间,其中存在j使得ai + d1 == ai+1(i<j) && ai + d2 == ai+1 (i>j) 构造:用c1[i], c2[i]记录i为标杆左边最多几个符合以及右边最多几个符合,那么i的贡献为(c1[i]+1) * (c2[i] + 1):当d1==d2时,找出符合的连续区间,长度记为cnt,那么贡献为(cnt+1) * cnt / 2. ;;) ; ; ;        ; ;        ;        ;          …

链接: http://acm.hdu.edu.cn/showproblem.php?pid=5400 Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 875    Accepted Submission(s): 386 Problem Description A sequence b1,b2,⋯,bn are called (d1,d2)…

Number Sequence Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 89984    Accepted Submission(s): 21437 Problem Description A number sequence is defined as follows: f(1) = 1, f(2) = 1, f(n) = (A…