Time travel Problem Description Agent K is one of the greatest agents in a secret organization called Men in Black. Once he needs to finish a mission by traveling through time with the Time machine. The Time machine can take agent K to some point (0…

Rating Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 872    Accepted Submission(s): 545Special Judge Problem Description A little girl loves programming competition very much. Recently, she h…

原题链接:http://acm.hdu.edu.cn/showproblem.php?pid=4870 原题: Rating Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 654    Accepted Submission(s): 415 Special Judge Problem Description    A little…

Time travel Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 1480    Accepted Submission(s): 327 Problem Description Agent K is one of the greatest agents in a secret organization called Men in B…

Crazy Typewriter Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 391    Accepted Submission(s): 109 Problem Description There was a crazy typewriter before. When the writer is not very sober, it…

Where is the canteen Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 1070    Accepted Submission(s): 298 Problem Description After a long drastic struggle with himself, LL decide to go for some…

网络预选赛的题目……比赛的时候没有做上,确实是没啥思路,只知道肯定是整数分解,然后乘起来素数的幂肯定是偶数,然后就不知道该怎么办了… 最后题目要求输出方案数,首先根据题目应该能写出如下齐次方程(从别人那里盗的……): a11*x1  ^  a12*x2  ^  ...  ^  a1n*xn=0 a21*x1  ^  a22*x2  ^  ...  ^  a2n*xn=0 ... an1*x1  ^  an2*x2  ^  ...  ^  ann*xn=0,Aij表示选的第j个数的第i个质数(可能…

高斯消元可以解决一系列DP序混乱的无向图上(期望)DP DP序 DP序是一道DP的所有状态的一个排列,使状态x所需的所有前置状态都位于状态x前: (通俗的说,在一个状态转移方程中‘=’左侧的状态应该在‘=’右侧的所有状态之后) 于是往往只有按DP序转移状态,才可以保证每个状态值的正确性 一道DP的状态序不是唯一的 常见的有: 某些DAG上dp按拓扑序转移: 某些树上DP先转移x点的子树,后转移x: 某些树上DP先转移x,后转移x点的子树: 线性DP左到右或右到左: 区间DP小到大: 某些记忆化搜…

[BZOJ2137]submultiple Description 设函数g(N)表示N的约数个数.现在给出一个数M,求出所有M的约数x的g(x)的K次方和. Input 第一行输入N,K.N表示M由前N小的素数组成.接下来N行,第i+1行有一个正整数Pi,表示第Ai小的素数 有 Pi次.等式: Output 输出一个数,表示答案.只需输出最后答案除以1000000007的余数. Sample Input 2 3 1 3 Sample Output 900 [样例说明] M=2^1*3^3=54…

HIGH - Highways no tags  In some countries building highways takes a lot of time... Maybe that's because there are many possiblities to construct a network of highways and engineers can't make up their minds which one to choose. Suppose we have a lis…