hdu 1496 Equations

Equations

题意:给定一个四元二次方程的系数a,b,c,d;问有多少个解；

a, b, c, d are integers from the interval [-50,50] and any of them cannot be 0.

It is consider a solution a system ( x1,x2,x3,x4 ) that verifies the equation, xi is an integer from [-100,100] and xi != 0, any i ∈{1,2,3,4}.

题目没有说清楚当a = b时，是否x1与x2可以看成一个即之后是乘以16还是要根据情况相乘；出题者意思是不考虑这些

思路:直接枚举两个x1,x2的可能的和值，在另外两个里面找出相反数的个数即可；用STL来查找重复元素的个数即可；

时间复杂度为O(n^2log(n^2)) n <= 100;

 

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转载于:https://www.cnblogs.com/hxer/p/5225816.html