杭電1014 Uniform Generator
4349 ワード
この問題は、していないで、直接以前のコードをコピーして来て、提出して、順調に通過しました.
後でまた見ました.
この問題は,擬似乱数の1つの繰返し周期における総和が必ず0からmod−1までのすべての整数の和以下であると推測する.(この推測も正しいかどうかはわかりませんが、関係者の指摘を歓迎します)
/* THE PROGRAM IS MADE BY PYY */
/*
http://acm.hdu.edu.cn/showproblem.php?pid=1014
Uniform Generator
Author: pyy
Begin : 16:00
End : 17:00
*/
#include
#include
using namespace std;
inline int prand();
int seed, step, mod;
int main()
{
int head, tail, decreasor = 0;
while (cin >> step >> mod && mod) {
decreasor = 0;
seed = 0;
//最初の乱数
head = prand();
//0からmod-1の範囲内なので、整数の合計
for (int i = 0; i < mod; i++)
decreasor += i;
//最初の乱数を引く
decreasor = decreasor - head;
//good choiceの場合、decreasorは2番目の繰り返しサイクル前に0に減少します
while (head != (tail = prand())) {
decreasor -= tail;
}
cout << setw(10) << step
<< setw(10) << mod
<< " ";
if (decreasor)
cout << "Bad Choice";
else
cout << "Good Choice";
cout << endl << endl;
}
return 0;
}
//乱数発生器
inline int prand()
{
seed = (seed + step) % mod;
return seed;
}
--------------------------------------------------------------------------------
Uniform Generator
Time Limit: 2000/1000 MS (Java/Others)Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 5562Accepted Submission(s): 2228
Problem Description
Computer simulations often require random numbers. One way to generate pseudo-random numbers is via a function of the form
seed(x+1) = [seed(x) + STEP] % MOD
where '%' is the modulus operator.
Such a function will generate pseudo-random numbers (seed) between 0 and MOD-1. One problem with functions of this form is that they will always generate the same pattern over and over. In order to minimize this effect, selecting the STEP and MOD values carefully can result in a uniform distribution of all values between (and including) 0 and MOD-1.
For example, if STEP = 3 and MOD = 5, the function will generate the series of pseudo-random numbers 0, 3, 1, 4, 2 in a repeating cycle. In this example, all of the numbers between and including 0 and MOD-1 will be generated every MOD iterations of the function. Note that by the nature of the function to generate the same seed(x+1) every time seed(x) occurs means that if a function will generate all the numbers between 0 and MOD-1, it will generate pseudo-random numbers uniformly with every MOD iterations.
If STEP = 15 and MOD = 20, the function generates the series 0, 15, 10, 5 (or any other repeating series if the initial seed is other than 0). This is a poor selection of STEP and MOD because no initial seed will generate all of the numbers from 0 and MOD-1.
Your program will determine if choices of STEP and MOD will generate a uniform distribution of pseudo-random numbers.
Input
Each line of input will contain a pair of integers for STEP and MOD in that order (1 <= STEP, MOD <= 100000).
Output
For each line of input, your program should print the STEP value right- justified in columns 1 through 10, the MOD value right-justified in columns 11 through 20 and either "Good Choice"or "Bad Choice"left-justified starting in column 25. The "Good Choice"message should be printed when the selection of STEP and MOD will generate all the numbers between and including 0 and MOD-1 when MOD numbers are generated. Otherwise, your program should print the message "Bad Choice". After each output test set, your program should print exactly one blank line.
Sample Input
South Central USA 1996
Recommend
JGShining
後でまた見ました.
この問題は,擬似乱数の1つの繰返し周期における総和が必ず0からmod−1までのすべての整数の和以下であると推測する.(この推測も正しいかどうかはわかりませんが、関係者の指摘を歓迎します)
/* THE PROGRAM IS MADE BY PYY */
/*
http://acm.hdu.edu.cn/showproblem.php?pid=1014
Uniform Generator
Author: pyy
Begin : 16:00
End : 17:00
*/
#include
#include
using namespace std;
inline int prand();
int seed, step, mod;
int main()
{
int head, tail, decreasor = 0;
while (cin >> step >> mod && mod) {
decreasor = 0;
seed = 0;
//最初の乱数
head = prand();
//0からmod-1の範囲内なので、整数の合計
for (int i = 0; i < mod; i++)
decreasor += i;
//最初の乱数を引く
decreasor = decreasor - head;
//good choiceの場合、decreasorは2番目の繰り返しサイクル前に0に減少します
while (head != (tail = prand())) {
decreasor -= tail;
}
cout << setw(10) << step
<< setw(10) << mod
<< " ";
if (decreasor)
cout << "Bad Choice";
else
cout << "Good Choice";
cout << endl << endl;
}
return 0;
}
//乱数発生器
inline int prand()
{
seed = (seed + step) % mod;
return seed;
}
--------------------------------------------------------------------------------
Uniform Generator
Time Limit: 2000/1000 MS (Java/Others)Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 5562Accepted Submission(s): 2228
Problem Description
Computer simulations often require random numbers. One way to generate pseudo-random numbers is via a function of the form
seed(x+1) = [seed(x) + STEP] % MOD
where '%' is the modulus operator.
Such a function will generate pseudo-random numbers (seed) between 0 and MOD-1. One problem with functions of this form is that they will always generate the same pattern over and over. In order to minimize this effect, selecting the STEP and MOD values carefully can result in a uniform distribution of all values between (and including) 0 and MOD-1.
For example, if STEP = 3 and MOD = 5, the function will generate the series of pseudo-random numbers 0, 3, 1, 4, 2 in a repeating cycle. In this example, all of the numbers between and including 0 and MOD-1 will be generated every MOD iterations of the function. Note that by the nature of the function to generate the same seed(x+1) every time seed(x) occurs means that if a function will generate all the numbers between 0 and MOD-1, it will generate pseudo-random numbers uniformly with every MOD iterations.
If STEP = 15 and MOD = 20, the function generates the series 0, 15, 10, 5 (or any other repeating series if the initial seed is other than 0). This is a poor selection of STEP and MOD because no initial seed will generate all of the numbers from 0 and MOD-1.
Your program will determine if choices of STEP and MOD will generate a uniform distribution of pseudo-random numbers.
Input
Each line of input will contain a pair of integers for STEP and MOD in that order (1 <= STEP, MOD <= 100000).
Output
For each line of input, your program should print the STEP value right- justified in columns 1 through 10, the MOD value right-justified in columns 11 through 20 and either "Good Choice"or "Bad Choice"left-justified starting in column 25. The "Good Choice"message should be printed when the selection of STEP and MOD will generate all the numbers between and including 0 and MOD-1 when MOD numbers are generated. Otherwise, your program should print the message "Bad Choice". After each output test set, your program should print exactly one blank line.
Sample Input
3 5
15 20
63923 99999
3 5 Good Choice
15 20 Bad Choice
63923 99999 Good Choice
South Central USA 1996
Recommend
JGShining