短文评估【安徽省选2003】- hash / trie

题目分析

其实是hash/trie裸题，讲一下hash的做法：如果其小写状态是第一次出现则加入集合，同时将小写状态加入小写单词的hash表，最后查时查出出现次数即可。

code

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<string>
#include<algorithm>
#include<vector>
#include<cmath>
#include<set>
using namespace std;

const int L = 40050;
typedef unsigned long long ull;
const ull Mod = 23333, H = 31;
ull oriHash, lowHash;
char s;
typedef long long ll;
ll q, p;
typedef pair<ull, ll> P;
vector<P> lowhash[Mod + 5];
vector<ull> S;

inline void low_insert(ull x){
	int key = x % Mod;
	for(int e = 0; e < lowhash[key].size(); e++)
		if(lowhash[key][e].first == x){
			lowhash[key][e].second++;
			return;
		}
	lowhash[key].push_back(P(x, 1));
}

inline ll low_query(ull x){
	int key = x % Mod;
	for(int e = 0; e < lowhash[key].size(); e++)
		if(lowhash[key][e].first == x)
			return lowhash[key][e].second;
	return 0;
}

inline void wr(ll x){
	if(x < 0) putchar('-'), x = -x;
	if(x > 9) wr(x / 10);
	putchar(x % 10 + '0');
}

int main(){
	while(scanf("%c", &s) != EOF){
		if('a' <= s&& s <= 'z'){
			lowHash = lowHash * H + (s - 'a' + 1);
			continue;
		}
		else if('A' <= s && s <= 'Z'){
			lowHash = lowHash * H + (s - 'A' + 1);
			continue;
		}
//		cout<<tmp<<" "<<q<<endl;
		if(lowHash){
			q++;
			if(!low_query(lowHash)) S.push_back(lowHash);
			low_insert(lowHash);
			lowHash = 0;
		}

	}
	if(lowHash){
		q++;
		if(!low_query(lowHash)) S.push_back(lowHash);
		lowHash = 0;
	}
	for(int i = 0; i < S.size(); i++){
		ull x = S[i];
		ll tt = low_query(x);
//		cout<<tt<<endl;
		p += pow(tt, 4);
	}
	wr(p), putchar(' '), wr(q);
	return 0;
}