【POJ3187 Backward Digit Sums 【暴搜】】的更多相关文章

POJ3187 Backward Digit Sums 【暴搜】

Backward Digit Sums Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 4487   Accepted: 2575 Description FJ and his cows enjoy playing a mental game. They write down the numbers from 1 to N (1 <= N <= 10) in a certain order and then sum ad…

（DFS、全排列）POJ-3187 Backward Digit Sums

题目地址 简要题意: 输入两个数n和m,分别表示给你1--n这些整数,将他们按一定顺序摆成一行,按照杨辉三角的计算方式进行求和,求使他们求到最后时结果等于m的排列中字典序最小的一种. 思路分析: 不难推得第一行为n个数a1\a2\--\an时求得的和为i=0∑n-1 ai*(n-1Ci) 根据此公式,考虑到数据量比较小,只需要将原本按递增顺序依次排列好的1--n按next_permutation给出的递增全排列顺序逐个代入,如果结果与m相等就停止循环即可. 参考代码: #include<stdi…

POJ-3187 Backward Digit Sums （暴力枚举）

http://poj.org/problem?id=3187 给定一个个数n和sum,让你求原始序列,如果有多个输出字典序最小的. 暴力枚举题,枚举生成的每一个全排列,符合即退出. dfs版: #include <iostream> #include <cstdio> #include <cmath> #include <vector> #include <cstring> #include <string> #include <…

POJ3187 Backward Digit Sums

给出杨辉三角的顶点值,求底边各个数的值.直接DFS就好了 #include<iostream> #include<cstdio> #include<cstring> #include<cstdlib> #include<algorithm> #include<queue> #include<set> #include<map> #include<vector> #include<cmath&g…

【POJ - 3187】Backward Digit Sums（搜索）

-->Backward Digit Sums 直接写中文了 Descriptions: FJ 和 他的奶牛们在玩一个心理游戏.他们以某种方式写下1至N的数字(1<=N<=10). 然后把相邻的数相加的到新的一行数.重复这一操作直至只剩一个数字.比如下面是N=4时的一种例子 3 1 2 4 4 3 6 7 9 16 在FJ回来之前,奶牛们开始了一个更难的游戏:他们尝试根据最后结果找到开始的序列.这已超过了FJ的思考极限. 写一个程序来帮助FJ吧 Input N和最后的和 Output 满足…

P1118 [USACO06FEB]Backward Digit Sums G/S

P1118 [USACO06FEB]Backward Digit Sums G/S 题解:  (1)暴力法.对1-N这N个数做从小到大的全排列,对每个全排列进行三角形的计算,判断是否等于N.  对每个排列进行三角形计算,需要O(N2)次.例如第1行有5个数{a,b,c,d,e},那么第2行计算4次,第3行计算3次-等等,总次数是O(N2)的.  a    b    c    d    e    a+b    b+c   c+d   d+e      a+2b+c b+2c+d c+2d+e   …

BZOJ1653: [Usaco2006 Feb]Backward Digit Sums

1653: [Usaco2006 Feb]Backward Digit Sums Time Limit: 5 Sec  Memory Limit: 64 MBSubmit: 207  Solved: 161[Submit][Status][Discuss] Description FJ and his cows enjoy playing a mental game. They write down the numbers from 1 to N (1 <= N <= 10) in a cer…

Backward Digit Sums（POJ　3187）

Backward Digit Sums Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 5495   Accepted: 3184 Description FJ and his cows enjoy playing a mental game. They write down the numbers from 1 to N (1 <= N <= 10) in a certain order and then sum ad…

Backward Digit Sums(暴力)

Backward Digit Sums Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 5664   Accepted: 3280 Description FJ and his cows enjoy playing a mental game. They write down the numbers from 1 to N (1 <= N <= 10) in a certain order and then sum ad…

1653: [Usaco2006 Feb]Backward Digit Sums

1653: [Usaco2006 Feb]Backward Digit Sums Time Limit: 5 Sec  Memory Limit: 64 MBSubmit: 285  Solved: 215[Submit][Status] Description FJ and his cows enjoy playing a mental game. They write down the numbers from 1 to N (1 <= N <= 10) in a certain orde…