Four operational procedures

For the generation of 30 random arithmetic, my first thought was this:

1, generate a random number.

2, control the generated random number within the appropriate range

3. Randomly select an operator

4. Randomly generate a second random number

5, control the generated random number within the appropriate range

6. Print output

This wrote a preliminary procedure:

Wang Wenchi Arithmetic

#include <iostream>

#include <string>

#include <iomanip>

#include <time.h>

using namespace Std;

void Main ()

{

int first, second,c,i;

String op;

Srand ((unsigned) time (NULL)); Make a Time seed

for (i = 0; i <; i++)

{

First = rand ()% 99; Generates a random integer within the first 0~99

c = 1 + rand ()% 4; Generates a random integer within 1~4

Switch (c)

{

Case 1:op = "+"; Break

Case 2:op = "-"; Break

Case 3:op = "x"; Break

Case 4:op = "÷"; Break

Default:break;

}

Second = rand ()% 99; Generates a random integer within the second 0~99

cout << SETW (3) << first << SETW (3) << op << setw (3) << second << SETW (3) <&L T "=" << Endl;

}

}

Picture 1 is the result of the run. It took about 30 minutes.

In order to achieve a true fractional operation, I divide it into 4 situations:

1, two numbers are integers;

2, the first is a true fraction, the second is an integer;

3, the first is an integer, the second is a true fraction;

4, two numbers are true scores.

True Fractional realization: Generate a random number of 0~99, generate a random number of 1~99, compare size, put small in front, large in the back, shape like: small/large.

In this way, the perfect program is written:

Wang Wenchi Arithmetic

#include <iostream>

#include <string>

#include <iomanip>

#include <time.h>

using namespace Std;

String oper (String op)

{

int C;

c = 1 + rand ()% 4; Generates a random integer within 1~4

Switch (c)

{

Case 1:op = "+"; Break

Case 2:op = "-"; Break

Case 3:op = "x"; Break

Case 4:op = "÷"; Break

Default:break;

}

return op;

}

void Number1 ()//two numbers are integers

{

String op;

int first, second;

First = rand ()% 99; Generates a random integer within the first 0~99

Second = rand ()% 99; Generates a random integer within the second 0~99

cout << SETW (3) << first << SETW (3) << oper (OP) << SETW (3) << second << SETW (3) << "=" << Endl;

}

void Number2 ()//The first is a true fraction, the second is an integer

{

String op;

int First1, first2, second,temp;

First1 = rand ()% 99; Generates a random integer within a 0~99

First2 = 1+rand ()% 99; Generates a random integer within a 1~99

if (FIRST1>FIRST2)

{

temp = First1;

First1 = First2;

First2 = temp;//Exchange, guaranteed First1<first2, and first2 not equal to 0

}

Second = rand ()% 99; Generates a random integer within the second 0~99

cout << SETW (3) << first1<< "/" <<first2 << SETW (3) << oper (OP) << SETW (3) <&L T Second << SETW (3) << "=" << Endl;

}

void Number3 ()//First is an integer, the second is a true fraction

{

String op;

int first, SECOND1, Second2, temp;

First = rand ()% 99; Generates a random integer within the first 0~99

Second1 = rand ()% 99; Generates a random integer within a 0~99

Second2 = 1 + rand ()% 99; Generates a random integer within a 1~99

if (SECOND1>SECOND2)

{

temp = Second1;

Second1 = Second2;

Second2 = temp;//Exchange, guaranteed Second1<second2, and second2 not equal to 0

}

cout << SETW (3) << first << SETW (3) << oper (OP) << SETW (3) << second1 << "/" < ;< second2 << SETW (3) << "=" << Endl;

}

void Number4 ()//two numbers are true fractions

{

String op;

int First1, First2, Second1, Second2, temp;

First1 = rand ()% 99; Generates a random integer within a 0~99

FIRST2 = 1 + rand ()% 99; Generates a random integer within a 1~99

Second1 = rand ()% 99; Generates a random integer within a 0~99

Second2 = 1 + rand ()% 99; Generates a random integer within a 1~99

if (FIRST1>FIRST2)

{

temp = First1;

First1 = First2;

First2 = temp;//Exchange, guaranteed First1<first2, and first2 not equal to 0

}

if (SECOND1>SECOND2)

{

temp = Second1;

Second1 = Second2;

Second2 = temp;//Exchange, guaranteed Second1<second2, and second2 not equal to 0

}

cout << SETW (3) << first1 << "/" << first2 << setw (3) << oper (OP) << SETW (3) < ;< second1 << "/" << Second2 << setw (3) << "=" << Endl;

}

void Main ()

{

int z,i;

Srand ((unsigned) time (NULL)); Make a Time seed

for (i = 0; i <; i++)

{

z = 1 + rand ()% 4; Generates a random integer within 1~4

cout << "section" << SETW (2) <<i + 1 << "title:";

Switch (z)

{

Case 1:number1 (); Break

Case 2:number2 (); Break

Case 3:number3 (); Break

Case 4:number4 (); Break

Default:break;

}

}

}

After the picture is complete, the result is running.

This process took about 40 minutes.

Four operational procedures