C++ Program to Generate Randomized Sequence of Given Range of Numbers

At first let us discuss about the rand() function. rand() function is a predefined method of C++. It is declared in header file. rand() is used to generate random number within a range. Here min_n is the minimum range of the random numbers and max_n is the maximum range of the numbers. So rand() will return the random numbers between min_n to (max_n – 1) inclusive of the limit values. Here if we mention lower and upper limits as 1 and 100 respectively, then rand() will return values from 1 to (100 – 1). i.e. from 1 to 99.

Algorithm

Begin
   Declare max_n to the integer datatype.
      Initialize max_n = 100.
   Declare min_n to the integer datatype.
      Initialize min_n = 1.
   Declare new_n to the integer datatype.
   Declare i of integer datatype.
   Print “The random number is:”.
   for (i = 0; i < 10; i++)
      new_n = ((rand() % (max_n + 1 - min_n)) + min_n)
   Print the value of new_n.
End.

Example

<span class="com">#include</span><span class="pln"> </span><span class="str"><iostream></span>
<span class="com">#include</span><span class="pln"> </span><span class="str"><stdlib.h></span>
<span class="kwd">using</span><span class="pln"> </span><span class="kwd">namespace</span><span class="pln"> std</span><span class="pun">;</span>
<span class="kwd">int</span><span class="pln"> main</span><span class="pun">() </span><span class="pun">{</span>
<span class="kwd">   int</span><span class="pln"> max_n </span><span class="pun">=</span><span class="pln"> </span><span class="lit">100</span><span class="pun">;</span>
<span class="kwd">   int</span><span class="pln"> min_n </span><span class="pun">=</span><span class="pln"> </span><span class="lit">1</span><span class="pun">;</span>
<span class="kwd">   int</span><span class="pln"> new_n</span><span class="pun">;</span>
<span class="kwd">   int</span><span class="pln"> i</span><span class="pun">;</span>
<span class="pln">   cout</span><span class="pun"><<</span><span class="str">"The random number is: \n"</span><span class="pun">;</span>
<span class="kwd">   for</span><span class="pln"> </span><span class="pun">(</span><span class="pln">i </span><span class="pun">=</span><span class="pln"> </span><span class="lit">0</span><span class="pun">;</span><span class="pln"> i </span><span class="pun"><</span><span class="pln"> </span><span class="lit">10</span><span class="pun">;</span><span class="pln"> i</span><span class="pun">++) </span><span class="pun">{</span>
<span class="pln">      new_n </span><span class="pun">=</span><span class="pln"> </span><span class="pun">((</span><span class="pln">rand</span><span class="pun">()</span><span class="pln"> </span><span class="pun">%</span><span class="pln"> </span><span class="pun">(</span><span class="pln">max_n </span><span class="pun">+</span><span class="pln"> </span><span class="lit">1</span><span class="pln"> </span><span class="pun">-</span><span class="pln"> min_n</span><span class="pun">))</span><span class="pln"> </span><span class="pun">+</span><span class="pln"> min_n</span><span class="pun">);</span>
<span class="com">      //rand() returns random decimal number.</span>
<span class="pln">      cout</span><span class="pun"><<</span><span class="pln">new_n</span><span class="pun"><<</span><span class="pln">endl</span><span class="pun">;</span>
<span class="pun">   }</span>
<span class="kwd">   return</span><span class="pln"> </span><span class="lit">0</span><span class="pun">;</span>
<span class="pun">}</span>

Output

The random number is:
42
68
35
1
70
25
79
59
63
65