优雅的字符串哈希写法

如果有CE, 显卡看是不是NT写错模数

template<typename hst,hst B,hst M>
struct hash_s{
	static hst phs[N];
	int len ; hst val;
	static void init(){
		phs[0] = 1;
		for(int i = 1; i < N; ++i) phs[i] = phs[i - 1] * B % M;
	}
	hash_s friend operator + (const hash_s& x,const hash_s& y){
		return {x.len + y.len, (x.val * phs[y.len] + y.val) % M};
	}
	friend hash_s operator - (const hash_s& x, const hash_s& y){
		return {x.len - y.len, ((x.val - y.val * phs[x.len - y.len]) % M + M) % M};
	}
	friend bool operator == (const hash_s& x, const hash_s& y){
		return x.len == y.len && x.val == y.val;
	}
};
template<typename hst,hst B,hst M>
hst hash_s<hst, B, M>::phs[N];

多模式串哈希封装是平凡的

原文地址：http://www.cnblogs.com/cdsidi/p/16908062.html