UVa 10924 Prime Words

質數題大屠殺的時候解的

	/*
	* UVa 10924 Prime Words (AC)
	* Author: chchwy
	* Last Modified: 2009.11.22
	*/
	#include<iostream>
	#include<sstream>
	#include<cctype>
	using namespace std;
	enum {MAX = 52 * 20 + 2};
	char p[MAX]; //0=prime, 1=not prime
	void shieve()
	{
	p[0] = p[1] = 0;
	for (int i = 2; i * i < MAX; ++i)
	{
	if (p[i] == 1) continue;
	for (int j = i * i; j < MAX; j += i)
	p[j] = 1;
	}
	}
	int main()
	{
	shieve();
	string line;
	while (getline(cin, line))
	{
	int sum = 0;
	//for each char
	for (int i = 0; i < line.length(); ++i)
	{
	if ( islower(line[i]) )
	sum += line[i] - 'a' + 1;
	else
	sum += line[i] - 'A' + 27;
	}
	if (p[sum] == 0)
	puts("It is a prime word.");
	else
	puts("It is not a prime word.");
	}
	return 0;
	}

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