RosettaCodeData/Task/Probabilistic-choice/C++/probabilistic-choice.cpp

53 lines
2.0 KiB
C++

#include <cstdlib>
#include <iostream>
#include <vector>
#include <utility>
#include <algorithm>
#include <ctime>
#include <iomanip>
int main( ) {
typedef std::vector<std::pair<std::string, double> >::const_iterator SPI ;
typedef std::vector<std::pair<std::string , double> > ProbType ;
ProbType probabilities ;
probabilities.push_back( std::make_pair( "aleph" , 1/5.0 ) ) ;
probabilities.push_back( std::make_pair( "beth" , 1/6.0 ) ) ;
probabilities.push_back( std::make_pair( "gimel" , 1/7.0 ) ) ;
probabilities.push_back( std::make_pair( "daleth" , 1/8.0 ) ) ;
probabilities.push_back( std::make_pair( "he" , 1/9.0 ) ) ;
probabilities.push_back( std::make_pair( "waw" , 1/10.0 ) ) ;
probabilities.push_back( std::make_pair( "zayin" , 1/11.0 ) ) ;
probabilities.push_back( std::make_pair( "heth" , 1759/27720.0 ) ) ;
std::vector<std::string> generated ; //for the strings that are generatod
std::vector<int> decider ; //holds the numbers that determine the choice of letters
for ( int i = 0 ; i < probabilities.size( ) ; i++ ) {
if ( i == 0 ) {
decider.push_back( 27720 * (probabilities[ i ].second) ) ;
}
else {
int number = 0 ;
for ( int j = 0 ; j < i ; j++ ) {
number += 27720 * ( probabilities[ j ].second ) ;
}
number += 27720 * probabilities[ i ].second ;
decider.push_back( number ) ;
}
}
srand( time( 0 ) ) ;
for ( int i = 0 ; i < 1000000 ; i++ ) {
int randnumber = rand( ) % 27721 ;
int j = 0 ;
while ( randnumber > decider[ j ] )
j++ ;
generated.push_back( ( probabilities[ j ]).first ) ;
}
std::cout << "letter frequency attained frequency expected\n" ;
for ( SPI i = probabilities.begin( ) ; i != probabilities.end( ) ; i++ ) {
std::cout << std::left << std::setw( 8 ) << i->first ;
int found = std::count ( generated.begin( ) , generated.end( ) , i->first ) ;
std::cout << std::left << std::setw( 21 ) << found / 1000000.0 ;
std::cout << std::left << std::setw( 17 ) << i->second << '\n' ;
}
return 0 ;
}