下标为负数的数组

下标为负数的数组

struct ary{
	int *g,ys;
	ary(int siz,int val=0){
		g=(int*)malloc(sizeof(int)*siz*2);ys=siz;
		fill(g,g+siz*2,val);
	}
	ary(){}
	int &operator [](int x){return g[ys+x];}
};