ELFhash字符串散列函数——HDU1004

Problem Description

Contest time again! How excited it is to see balloons floating around. But to tell you a secret, the judges' favorite time is guessing the most popular problem. When the contest is over, they will count the balloons of each color and find the result.

This year, they decide to leave this lovely job to you.

 

 

Input

Input contains multiple test cases. Each test case starts with a number N (0 < N <= 1000) -- the total number of balloons distributed. The next N lines contain one color each. The color of a balloon is a string of up to 15 lower-case letters.

A test case with N = 0 terminates the input and this test case is not to be processed.

 

 

Output

For each case, print the color of balloon for the most popular problem on a single line. It is guaranteed that there is a unique solution for each test case.

 

 

Sample Input

   
   
   
   

    
    
    
    5
    
    
    
    

green
    
    
    
    

red
    
    
    
    

blue
    
    
    
    

red
    
    
    
    

red
    
    
    
    

3
    
    
    
    

pink
    
    
    
    

orange
    
    
    
    

pink
    
    
    
    

0
   
   
   
   

 

 

Sample Output

   
   
   
   

    
    
    
    red
    
    
    
    

pink
    
    
    
    


    
    
    
    


    #include <iostream>
#include <cstring>
using namespace std;

#define table_size 10000

int ELFhash(char* key, long M) {
	unsigned long h = 0;
	while(*key) {
		h = (h << 4) + *key++;
		unsigned long g = h & 0xF0000000L;
		if (g) h ^= g >> 24;
		h &= ~g;
	}
	return h % M;
}


int main(){
	char key[15];
	int cnt,n;
	while(cin >> n){
		if(!n) break;
		cnt = n;
		int table[table_size] = {0};
		char color[15];
		int max = 0;
		int hash;
		while(cnt--){
			cin >> key;
			hash = ELFhash(key, table_size);
			++table[hash];
			if(table[hash] > max){
				max = table[hash];
				strcpy(color, key);
			}
		}
		cout << color << endl;
	}
	return 0;
}