public member function
<random>
| (1) | explicit uniform_int_distribution ( result_type a = 0, result_type b = numeric_limits<result_type>::max() ); |
|---|
| (2) | explicit uniform_int_distribution ( const param_type& parm ); |
|---|
Construct uniform discrete distribution
Constructs a uniform_int_distribution object, adopting the distribution parameters specified either by a and b or by object parm.
Parameters
- a, b
- Upper and lower bounds of the range ([a,b]) of possible values the distribution can generate.
Note that the range includes both a and b (along with all the integer values in between).
b shall be greater than or equal to a (a<b).
result_type is a member type that represents the type of the random numbers generated on each call to operator(). It is defined as an alias of the first class template parameter (IntType).
- parm
- An object representing the distribution's parameters, obtained by a call to member function param.
param_type is a member type.
Example
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
|
// uniform_int_distribution example
#include <iostream>
#include <chrono>
#include <random>
int main()
{
// construct a trivial random generator engine from a time-based seed:
unsigned seed = std::chrono::system_clock::now().time_since_epoch().count();
std::default_random_engine generator (seed);
std::uniform_int_distribution<int> distribution(1,100);
int guess;
int number = distribution(generator);
while (true) {
std::cout << "guess the number (between 1 and 100): ";
std::cin >> guess;
if (number==guess) {std::cout << "right!\n"; break; }
else if (number>guess) std::cout << "it's greater\n";
else std::cout << "it's less\n";
}
return 0;
}
|
Possible output:
guess the number (between 1 and 100): 50
it's greater
guess the number (between 1 and 100): 75
it's greater
guess the number (between 1 and 100): 87
it's less
guess the number (between 1 and 100): 81
it's less
guess the number (between 1 and 100): 78
it's less
guess the number (between 1 and 100): 76
right!
|