【csp模拟赛5】购物（shopping.cpp）--常规

　　多项式，因为每次的x相同，所以把a和b相加就行了，然后找对称轴，找离对称轴最近的整数点，然而我却写了个暴力，没看x

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
using namespace std;
const int N = 100005;
inline int read()
{
	int x = 0 , f = 1;	char ch = getchar();
	while(ch < '0' || ch > '9')	{if(ch == '-')	f = -1; ch = getchar();}
	while(ch >= '0' && ch <= '9') {x = (x << 3) + (x << 1) + (ch ^ 48); ch = getchar();}
	return x * f;
}
int T , n , m;
long long a , b , c;
int main()
{
	freopen("shopping.in","r",stdin);
	freopen("shopping.out","w",stdout);
	T = read();
	while(T --> 0)
	{
		a = 0; b = 0; c = 0;
		n = read(); m = read();
		for(int i = 1;i <= n;i ++) {a += read(); b += read(); c += read();}
		double tmp = (double)b / ((double)a * (double)(-2));
		tmp = max(tmp,(double)1); tmp = min(tmp,(double)m);
		double res = floor(tmp);
		printf("%d
",(tmp - res) < 0.50000000 ? (int)res : (int)res + 1);
	}
	fclose(stdin);
	fclose(stdout);
	return 0;
}