Eqs Time Limit: 5000MS   Memory Limit: 65536K Total Submissions: 14093   Accepted: 6927 Description Consider equations having the following form: a1x13+ a2x23+ a3x33+ a4x43+ a5x53=0 The coefficients are given integers from the interval [-50,50]. It i…

a1x13+ a2x23+ a3x33+ a4x43+ a5x53=0,xi∈[-50,50],且xi!=0.让我们求所有解的可能. 首先,如果暴力判断的话,每个x的取值有100种可能,100^5肯定会超时. 我们可以枚举x1,x2的值,并且记录下来.再枚举x3,x4,x5的值.如果发现有互为相反数的,说明有一个解存在.复杂度却大大降低了. 当然,我们可以只处理正数的情况.如果存在一组解,x1,x2,x3,x4,x5,那么容易证明-x1,-x2,-x3,-x4,-x5也是一组解. 我们只记录a1…

Eqs Time Limit: 5000MS   Memory Limit: 65536K Total Submissions: 14169   Accepted: 6972 Description Consider equations having the following form:  a1x13+ a2x23+ a3x33+ a4x43+ a5x53=0  The coefficients are given integers from the interval [-50,50].  I…

题目 http://poj.org/problem?id=1840 题意 给 与数组a[5],其中-50<=a[i]<=50,0<=i<5,求有多少组不同的x[5],使得a[0] * pow(x[0], 3) + a[1] * pow(x[1], 3) + a[2] * pow(x[2], 3) + a[3] * pow(x[3], 3) + a[4] * pow(x[4], 3)==0 其中x[i]满足-50<=x[i]<=50,0<=i<5 思路 该等式…

题目链接:http://poj.org/problem?id=1840 题意:公式a1x1^3+ a2x2^3+ a3x3^3+ a4x4^3+ a5x5^3=0,现在给定a1~a5,求有多少个(x1~x5)的组合使得公式成立.并且(x1~x5)取值再[-50,50]且不能为0 思路:因为x的值范围比较小,只有100.所以可以先求出 a1x1^3+a2x2^3+a3x3^3. 然后在求 (-1)*(a4x4^3+a5x5^3)从前面的所得的Hash表进行二分查找. #include<iostre…

题目:http://poj.org/problem?id=1840 题解:http://blog.csdn.net/lyy289065406/article/details/6647387 小优姐讲的很好了 #include<cstdio> #include<string> #include<iostream> #include<cstring> #include<map> using namespace std; ]; int main() {…

Description Consider equations having the following form: a1x13+ a2x23+ a3x33+ a4x43+ a5x53=0 The coefficients are given integers from the interval [-50,50]. It is consider a solution a system (x1, x2, x3, x4, x5) that verifies the equation, xi∈[-50,…

题目链接:http://poj.org/problem?id=1804 题意:给定一个序列a[],每次只允许交换相邻两个数,最少要交换多少次才能把它变成非递降序列. 思路:题目就是要求逆序对数,我们知道,求逆序对最典型的方法就是树状数组,但是还有一种方法就是Merge_sort(),即归并排序.实际上归并排序的交换次数就是这个数组的逆序对个数,归并排序是将数列a[l,h]分成两半a[l,mid]和a[mid+1,h]分别进行归并排序,然后再将这两半合并起来.在合并的过程中(设l<=i<=mid…

Description Consider equations having the following form: a1x1 3+ a2x2 3+ a3x3 3+ a4x4 3+ a5x5 3=0 The coefficients are given integers from the interval [-50,50]. It is consider a solution a system (x1, x2, x3, x4, x5) that verifies the equation, xi∈…

Description Consider equations having the following form: a1x13+ a2x23+ a3x33+ a4x43+ a5x53= The coefficients are given integers ,]. It ,], xi != , any i∈{,,,,}. Determine how many solutions satisfy the given equation. Input The only line of input co…